The invention discloses a soft package non-modular power battery system which comprises an upper cover and a lower box body assembly which are fixedly connected, and a battery management system, a pressing rod assembly, a low-voltage wiring harness, a soft package battery cell assembly, a high-voltage assembly, a cross beam assembly and a liquid cooling system are sequentially arranged between theupper cover and the lower box body assembly from top to bottom. According to the technical scheme, a modular structure is avoided, soft package battery cells are directly integrated into the batterybox, the process of integrating the battery cells into a module is omitted, the assembly error caused by intermediate integration of the module is omitted, the process is simplified, and the cost is reduced; the system is non-modular, materials such as a module shell, a module end plate and a heat conduction structural adhesive are omitted, the weight is obviously reduced, the cost is obviously reduced, a heat exchange path is changed into a battery cell, heat conduction structural adhesive and liquid cooling pipe, the heat transfer path is shortened, and the efficiency is improved.