Floating seedling hardening method for potato test-tube plantlets

The invention provides a floating seedling hardening method for potato test-tube plantlets. The method comprises the following steps: selecting an open area to build an arched shed, forming an underground water tank in the arched shed, and covering the inner wall of the tank with a black plastic film; selecting foam floating hole trays with bottom holes at the bottoms of holes; mixing a matrix material rich in organic matters and a hydrophobic material to obtain a culture medium, filling the culture medium into the foam floating hole trays, transplanting tissue culture seedlings, selecting the potato tissue culture seedlings which grow strongly, have non-yellow leaves and are pollution-free, pouring the tissue culture seedlings out of culture bottles, cutting off overlong root systems, cleaning the culture medium remained on the root systems, clamping the tissue culture seedlings by tweezers and inserting the seedlings into the foam floating hole trays, moving the foam floating hole trays into the arched shed