Abstract: Small-and medium-scale biogas systems are widely distributed in China. Nevertheless, the overall strategic planning of biogas project is highly difficult, due mainly to the large difference in geographic regions. According to the different daily production of biogas (Q), biogas projects in China can be divided into four categories: extremely large (Q>5 000 Nm3/d), large (5 000 Nm3/d>Q>500 Nm3/d), medium (500 Nm3/d>Q>150 Nm3/d), and small (150 Nm3/d>Q>5 Nm3/d). At present, there are more than 100 000 biogas projects of various types in China, among which there are more than 66 000 large-scale biogas projects, more than 10 000 medium-sized biogas projects, and more than 80 000 small-scale biogas projects. Many previous studies focused on biogas purification on the large and super large biogas engineering, serving as the future development trend of industrialization. Purified biogas after purification can be used for vehicle fuel or incorporated into the natural gas pipeline network, thereby to achieve its high value usage. The fermentation of raw materials in small-and medium-sized biogas projects are usually from village wastes and manure from farms. There are still problems in the small-and medium-scale biogas system, such as regional dispersion, large quantity, difficulty in the overall planning, high purification cost, and low efficiency. The generated biogas is mostly used in low-value utilization ways, such as cooking, lighting, and power generation, far beyond the high-value utilization. Therefore, it is very urgent to extend the potential application of purification system in the small and medium-sized biogas projects. In this study, a set of skid-mounted integrated biogas purification system was designed, aiming to improve the efficiency, performance, and cost-saving systems in small- and medium-sized biogas projects. Technical methods were designed suitable for the manufacture system of desulfurization, decarburization, and control. Specifically, the dry desulfurization, membrane decarburization, and molecular sieve technology were integrated into the set of the system. An engineering application test was carried out, under the conditions of biogas intake capacity of 500 m3/d, and biogas pressure of 104 kPa. After 35 minutes of stable operation, the content of CH4 in the purified biogas reached 97.88%, the content of CO2 was lower than 2.5%, the content of H2S was as low as 11 mg/kg, and the recovery efficiency of CH4 reached 86.5%. The operating cost of equipment was 0.09 yuan/Nm3 biogas, and the payback period was only 1.5 a. In comparison, the purification performance of the apparatus met the requirements of biological natural gas standard of China, indicating the advantages of flexible movement, high purification efficiency, and low cost. To meet the needs of different engineering requirements for biogas purification equipment, the device can be designed, according to different material gas in different biogas producing scale. The stability of adjusted equipment was still needed to improve in the further, particularly on the equipment adaptability, and stability characteristics for the different types of biogas engineering. The application of this apparatus can realize the valorization of biogas, and further widen the fields for the development of small and medium-sized biogas projects.