The invention provides a film mulching cultivation method for potatoes. The film mulching cultivation method is characterized by including the following steps: (1) selecting and fertilizing a field, and performing soil preparation and ridging; (2) performing sowing; (3) simultaneously coating every two adjacent ridges by biodegradable weeding mulching films which are tightly attached to the corresponding ridge surfaces, and performing earthing-up between every two adjacent ridges by an earthing-up machine; (4), performing field management and harvesting. The film mulching cultivation method integrates film mulching with film-surface soil compaction and film-surface earthing-up, the planting process of the potatoes is simplified, and the working efficiency is greatly improved.