Abstract: Abstract: In order to solve the problems of the traditional form of rural household biogas digesters such as long construction cycle, short life, poor sealing, integrated production prices, and hard transportation, in this study we combined with the existing technology and technologic design to build a variable volume of polyvinyl chloride (PVC) plastic biogas digesters. The cell body from the PVC veneer and the support were made through the silicone rubber paste in accordance with the processing of a good groove bonding. Silicone rubber has good adhesion and waterproof sealing. The presence of the groove can provide a certain degree of reference, but also increase the bond strength and sealing. The tank body structure was simple, easy to assemble, and the assembly cycle was 1-2 days. Veneer can be stacked transport to save the overall delivery of high freight and inconvenience. Without increasing the design, processing requirements, users can easily expand the volume based on their requirement, the volume of the pool can be variable in the 3-20 m³. Design and processing of biogas digesters mainly consisted of four parts, the left pool body, from which its main role was to feed, the middle pool body, which mainly played a connection role and the use of Sheng satisfied biogas, right pool body, the main role of which was to discharge biogas slurry, and the pressure chamber, mainly used to contain excess liquid and to ensure the pressure inside the pool body. The tank body was easy to feed, the slag was more convenient according to the pressure difference effect. The pressure of soil layer was 1 800 N. When the gas pool was in work situation, it also would be affected by lateral soil load and biogas slurry pressure and the pressure of the gas. The 9 m³ cell structure designed by finite element verification was able to withstand the soil pressure and the external force. To the biogas digesters filled with sufficient water and gas, the barometer and scale were used to check the pool of internal pressure and water. Verification of adhesive and groove assembly structure was conducted in the 24 h experiment to test water and gas leakage. The gas pressure inside the cell body decreased from 10 kPa to 9.88 kPa, and the leakage rate of the cell body was 1.2%. For pool body leakage steam was less than 2% of national standard, so the structure can ensure the sealing performance of the pool. The cell body was measured at room temperature for 1 month of production at room temperature and 90% of the volume of the container. The results showed that the daily production of gas up to 1.380 m³, the effective pool volume gas production rate of 0.22 m3/(m3•d), gas production to meet a 3-5 mouth of life gas demand. The water temperature aging experiment was made for the pool parts under 70, 80, 90 ℃. With the cell body strength decreased by 50% as the standard, through the Allenitz formula extrapolation pool body in the flooding environment operating temperature of 30 ℃ service life. The results showed that the whole cell body under normal conditions of use, the cell life can up to 20.9 years.