Cleaning is a key process in the manufacturing process of hybrid detector chip devices. The organic contamination adsorbed on the surface of the detector chip is the main target of cleaning. The cleaning mechanism of organic contaminations (mainly composed of 502) on the InSb surface by acetone and ethyl acetate was studied using a combination of first principle and molecular dynamics. The first principles calculation results indicate that the molecular reaction active sites of acetone and ethyl acetate are both delocalized on heteroatoms, and both can achieve the purpose of cleaning by desorbing 502 adsorbed on the InSb surface through heteroatoms. The molecular dynamics simulation results indicate that ethyl acetate can promote the diffusion ability of acetone molecules in the 502 film layer, thereby enhancing the removal effect of acetone on 502.