Flow cytometry allows for the simultaneous detection of multiple cellular markers. It serves as a crucial tool for the efficient analysis of cells and a comprehensive understanding of cellular functions and disease mechanisms. The optical fixtures and components of the multichannel flow cytometry laser platform are susceptible to minor displacements due to environmental temperature, which can lead to deviations in spot spacing and changes in laser delay, ultimately affecting the accuracy of detection results. A laser platform with combined heating and heat dissipation for temperature control is designed to mitigate these effects. Finite element simulation is used to analyze the steady-state temperature distribution of the laser platform at different environmental temperatures, and spot spacing at different environmental temperatures is measured using a digital microscope. Finally, the instrument resolution is evaluated using the coefficient of variation of the full peak width. Experimental results show that after adding the temperature control system, the maximum temperature difference between the laser platform and the laser diode decreases by 4.7 ℃, and the maximum relative deviation in spot spacing is also reduced to 0.86%. The coefficient of variation of the full peak width is ≤2.4%, surpassing the YY/T 0588—2017 industry standard for flow cytometry, which requires a variation of the full peak width of ≤3.0%.