Using multicolor autofluorescent plant pollen grains and flower buds as samples, the performance of confocal laser scanning microscopy (CLSM) and optical sectioning structured illumination microscopy (OS-SIM) are compared under similar imaging conditions for multi-channel 3D imaging. Results demonstrate that OS-SIM achieves one order of magnitude faster imaging speed than conventional single-point scanning CLSM due to its wide-field imaging mechanism. Additionally, OS-SIM reduces photodamage by three orders of magnitude by employing LED illumination instead of laser excitation. The modular design of OS-SIM also lowers system costs to less than half that of CLSM. This study provides a more cost-effective solution for multicolor live-cell fluorescence imaging, highlighting technical and economic advantages of OS-SIM for applications such as dynamic 3D cell tracking and neural activity monitoring.