IMSP is the versatile rst-light instrument under construction for the 4m telescope in China. The special feature of IMSP is the multimode operation modes and high-e ciency. Direct imaging mode is designed to work in a synchronous multi-color bands covering from 360 to 1700 nm using two dichroic mirrors with a 3'x3' eld of view (FOV). Long-slit spectrograph mode supports two spectral resolutions operation modes (R=1000 & 5000) via di erent combination of Volume Phase Holographic Prisms to cover the whole spectrum in visible. High resolution spectrograph mode (R=30000-60000) with wavelength range from 380 to 800 nm is reserved using ber link system connected from Nasmyth foci to the enviroment controled room. The IMSP is planned to strart commssion at the end of 2021. In this paper, the lastest status of IMSP development will be given, including the nal optical design and the integration of each sub-system.