Hybrid battery thermal management system (BTMS) has received a lot of attention lately because of its excellent heat dissipation. However, the performance of hybrid BTMS is impacted by several elements, including basic technologies, structural design, and control methods. To improve the temperature and temperature uniformity of prismatic batteries, a novel hybrid BTMS composed of the U-shaped micro heat pipe array (U-MHPA) and the liquid cold plate filled with composite phase change material (cPCM) was proposed. Furthermore, a performance evaluation method and delayed cooling strategy were proposed and used to optimize the hybrid BTMS. Results showed that adhering a U-MHPA to the surface of the battery can effectively mitigate temperature non-uniformity in the prismatic battery. The cold plate filled with cPCM addressed the issue of significant temperature gradients parallel to the long flow direction of the cold plate. Compared to the single liquid cooling, the hybrid BTMS exhibited outstanding cooling performance under extreme operating conditions, reducing the Tmax of the battery module by 4.2 °C and the ΔTmax by 8.39 °C. The delayed cooling strategy based on the principles of phase change reduced the energy consumption of the hybrid thermal management system by 41.7%.