The invention discloses a photovoltaic polymer battery pack with built-in protection, including a lithium battery shell, the outer surface of the lower end of the lithium battery shell is fixedly connected with a bottom plate, A top insulating block is fixedly connected to an outer surface of one side of the lithium battery shell, The outer surface of one side of the top insulating block is fixedly connected with a negative electrode lug and a positive electrode lug, and the negative electrode lug is positioned behind the positive electrode lug; the outer surface of the upper end of the bottomplate is fixedly connected with a positive electrode plate, and the outer surface of one side of the positive electrode plate is fixedly connected with a positive electrode block; and an isolation film and a negative electrode plate are arranged above the positive electrode block. The built-in protective photovoltaic polymer battery pack of the invention is provided with a protective plate, a temperature detector, a conductive agent and a thickening agent, which can reduce the loss when the battery fails, can control the temperature inside the battery, can make the discharge rate of the lithium battery higher, and brings better application prospects.