This paper presents a comprehensive analysis of a novel two-stage cascade thermoelectric cooler (TTEC). The novel TTEC may be simply formed by joining short-legged thermoelectric couples in cascade, which has advantages of no interstage electrical insulating materials, compact and easy-fabricated structure, and using only one operating power. An analytical model taking into account the allocation of the total input current between the two stages of the TTEC is developed and the performance characteristics are investigated in detail. Especially, the allocation ratio of thermoelectric couple leg length which maximizes the TTEC COP at a specified condition are discussed. The analysis results indicate that such a cascade TTEC can greatly improve the operating temperature difference and be in theory more efficient than a single-stage thermoelectric cooler under most circumstances. It is also revealed that the allocation ratio of thermoelectric couple leg length plays an important role in determining TTEC thermal performance. Overall, the presented TTEC may show its promise in the future electronics cooling applications.