The invention provides a bending-preventing water draining device for reinforcing soft soil foundation through vacuum preloading. The bending-preventing water draining device comprises horizontal water draining passages connected through a connection joint; connecting ports are formed in the connection joint; water draining plates are inserted in the connecting port and are of hollow structures; vertical partition boards and vertical reinforcing ribs are arranged in the water draining plates; and the outer walls of the water draining plates are wrapped with filtering films. The bending-preventing water draining device improves the anti-bending and anti-fracture performance of the water draining plates on the basis of ensuring the water draining effect, realizes the situation that the waterdraining plates do not bend due to differential settlement of foundation soil during the process of reinforcing dredger fill through vacuum preloading and ensures the perpendicularity of the water draining plates during the entire reinforcing process; and at the reinforcing later period, the vacuum degree transmission efficiency and the water draining rate do not reduce obviously, so that the reinforcing effect is greatly improved.