In view of the high requirements for temperature control stability of multi-channel surface plasmon resonance (SPR) sensing systems in the detection process of biomolecular interactions, this study designs and implements a separable local constant temperature system. Taking the thermoelectric cooler (TEC) as the core executive component, this system combines oxygen-free copper clamps, digital temperature control modules, thermistor temperature sensors and air-cooled heat dissipation structures to realize local temperature regulation of the sensing area of SPR microfluidic chips. The experimental results show that the system can achieve stable temperature control in a wide temperature range from 15℃ to 45℃, and the temperature fluctuation range is less than ±0.05℃. After the optimization of external constant temperature compensation, the difference between the actual temperature and the set value in the chip sensing area can be controlled within 0.47℃. After being integrated with the SPR imaging system, the average baseline noise is reduced by 13.3%. The temperature control system designed in this study has the advantages of compact structure, separable form and high temperature control accuracy, which is suitable for multi-channel SPR biosensing systems.