The invention relates to a polymer lithium battery with good heat dissipation performance, which comprises a placing frame, a sealing plate is fixed at the left end of the placing frame through screws, ventilation grooves are uniformly formed in the sealing plate, battery cells wrapped by aluminum-plastic composite films are uniformly placed in the placing frame, and the battery cells are connected in series through wires. According to the invention, the following problems existing in the combination and use process of the existing polymer lithium battery can be solved: a, directly binding the existing polymer lithium batteries together during combined use, and wrapping by using an aluminum-plastic composite film; b, the polymer lithium batteries which are combined and wrapped together cannot be quickly separated when the temperature of the batteries is high, only spontaneous combustion cooling of the polymer lithium batteries can be waited, the cooling speed is low, and consumed time is long.