The invention discloses a hidden type floor prevention system which comprises a main trough body (1), a water baffle (2), a power system and an auxiliary supporting structure, wherein guide rails (3) are arranged on the left and right sides of the main trough body (1); a water drainage slot (5) is formed in the lower portion of the main trough body (1); a horizontal protection plate (9) is arranged on the upper end surface of the water baffle (2); the power system comprises an electric hoist (10) and a manual winch (11); the auxiliary supporting structure comprises vertically arranged supporting rods (16) and horizontally arranged puller bolts (17); the supporting rods (16) are provided with threaded holes (18); and the puller bolts (17) penetrate through the threaded holes and then are in contact with the water baffle (2). By simultaneously arrangement of the electric hoist and the manual winch, the automation property of the hidden type floor prevention system is effectively improved; and furthermore, by additional arrangement of the auxiliary supporting device on the inner side of the water baffle, the flood prevention performance of the hidden type floor prevention system is effectively improved.