Aiming at enhancing the mechanization level of potato cultivation, promoting the development of potato industry, and further integration agronomic requirement of seedlings emerge cultivation pattern of potato self-puncture with covering soil on the film, a combined potato planting machine was designed, which synchronously realized institutional operation, such as fertilization, seeding, ridging, film mulching and covering soil on the top of full film surface. Based on the prototype, key parts were designed and selected, and the structure and operation parameters of fertilizing system and chain-spoon potato metering device were determined. The operation process of covering soil on the top of full film surface was analyzed, and the necessary work conditions to make sure that the covering soil thickness on the top of full film surface were obtained by analysis and calculation. For the relevant work performance test of prototype, the field experimental results showed that under the condition of operation speed of 1.8~2.0km/h, the multiple index was 4.9%, the missing index was 6.6%, the qualification rate of planting depth was 95.2%, the potato distance qualified index was 90.1%, the qualification rate of covering soil on the top of full film surface was 98.8%, the variation coefficient of fertilizer consumption consistency for each row was 6.5%, and the variation coefficient of fertilizer consumption stability for the total row was 5.1%, which were up to the relevant work quality evaluation specification requirements, and also the experimental results met the design requirements of combined operation machine. The research results provided an important reference for the plastic film mulching cultivation pattern of root-tuber crop combined machine development.