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1. Ensure the airtightness of the biogas digester; sealing should be a priority during its construction. Once all parts of the tank have reached a certain strength, it is necessary to check whether the biogas tank is leaking water or gas. Inspect the plaster layer in various areas of the tank for any cracks or peeling, and check the surface of the tank for any honeycombing or visible capillary pores. Also, tap on the surface to listen for any hollow sounds. If there are cells and visible capillaries, grouting should be continued using sealing techniques ； Any holes or cracks should be chipped out and redone. 2. Raise the fermentation temperature in the tank: ① Use heating to accelerate decomposition. When replacing or adding material to the biogas digester, an appropriate amount of warm water can be added to raise the temperature inside the digester, aiming to keep it above 5°C to facilitate the decomposition of the new material and gas production. ②Insulation coverage. Insulating materials such as crop straws, firewood, compost, or an increased soil layer should be placed on the surface of the biogas digester, with the coverage area needing to be larger than the surface of the digester itself in order to prevent cold air from entering. ③Dig a ring-shaped trench for insulation. Dig circular ditches around the biogas digester; pile manure and grass in these ditches to facilitate fermentation, generate heat, and maintain warmth. ④Insulation for plastic sheds. On the sunny side of pigsties, sheep pens, chicken coops, cowsheds and other livestock shelters, plastic film is laid, or the entire top of the biogas digester is covered with plastic film. Straw is used to construct the biogas digester, and the plastic film is extended 2–3 meters outward so that it can cover the feed inlet, discharge outlet, water inlet, as well as the surrounding ground, thereby raising the temperature inside the digester. 3. Prepare high-quality inoculum: When it is difficult to obtain a large amount of inoculum, this issue can be resolved by using the fermentation residues from old biogas digesters and adding a certain amount of human, animal, or poultry manure for cultivation. To prepare 1000 kilograms of fermentation inoculum, 400 kilograms of biogas fermentation broth and 600 kilograms of human, animal, and poultry manure are generally added, then mixed together. The mixture is placed in a water-proof pit and sealed with plastic film; after 7 days, it can be used as an inoculum ； If biogas fermentation liquid is not available, 500 kilograms of sludge from ditches in rural areas that have not been used for a long time can be used, along with 500 kilograms of human and livestock manure; after mixing, the mixture should be left to ferment for more than 7 days before it can be used. 4. Preventing external water from entering: Every effort must be made to stop external water from getting into the biogas digester, in order to avoid a decrease in the concentration of the feed liquid and the temperature inside the digester. 5. Adjust the pH value of the biogas fermentation liquid in the tank; its acidity or alkalinity can be tested using pH test strips. When the pH value is below 7, slowly adjust it to between 7 and 7.5 using 1% lime water (use with caution to avoid excess alkalinity), in order to meet the requirements of the fermentation bacteria. 6. Addition of fermentation inhibitors is strictly prohibited. To protect the biota involved in biogas fermentation from damage, it is essential to avoid adding any large amounts of fermentation inhibitors, especially **pesticides and various strong fungicides.