The invention relates to the field of mechanical equipment, in particular to a multi-channel polar plate discharge device capable of smoothly sliding on a rail. According to the technical scheme adopted by the invention, the multi-channel polar plate discharge device capable of smoothly sliding on the rail comprises a discharge drive device, a discharge guide rail and a plurality of discharge slide parts which are driven by the discharge drive device to slide along the discharge guide rail; each discharge slide part comprises a slide car; the slide car comprises wheels; the discharge guide rail comprises a linear part and a curve part; the curve part is a circular arc which is tangential to a straight line where the linear part lies; and the discharge guide rail comprises an outer rail and an inner rail positioned on the inner ring of the outer rail. The invention aims to provide the multi-channel polar plate discharge device capable of smoothly sliding on the rail, the multi-channel polar plate discharge device can operate a plurality of polar plates once, the discharge slide parts smoothly slide on the discharge guide rail, and normally slide on the linear part and the curve part.