The invention discloses a surface spraying device for composite door manufacturing. The surface spraying device for composite door manufacturing comprises spraying nozzles, a composite door body, a spraying box, a spraying chamber, a lower fixed hook, pull rings, a guide post I, a screw rod I, a side shell I, a movable seat I, connectors, hoses, an upper shell, a driven pulley, a belt, a motor, adriving pulley, a screw rod II, a side shell II, an upper fixed hook, a guide post II and a movable seat II. The surface spraying device for composite door manufacturing is reasonable and simple in structure, low in production cost, convenient to install and complete in function. Firstly, the pull rings are fixed to technological threaded holes in the upper and lower surfaces of the composite doorbody, then the pull rings are tightly hooked in the lower fixed hook and the upper fixed hook, and thus it is guaranteed that the composite door body is in a vertical position and spraying is conveniently conducted through the praying nozzles. During spraying, paint enters the spraying nozzles through the connectors and the hoses, the left and right surfaces of the composite door body are sprayedsimultaneously, and thus spraying efficiency is greatly improved.