In order to explore the effect of Si doping on the negative thermal expansion (NTE) and magnetic properties of antiperovskite Mn3Zn0.6Ge0.4N, a series of Si-doping Mn3Zn0.6SixGe0.4-xN（x=0、0.1、0.15、0.2）materials were prepared by spark plasma sintering (SPS). The powder X-ray diffraction measurement was conducted in order to characterize the structures of the products, the results of which manifest that the products have the space group Pm-3m, indicating that the Mn3Zn0.6SixGe0.4-xN（x=0、0.1、0.15、0.2）materials were successfully synthesized. Furthermore, we characterized the thermal expansion property of Mn3Zn0.6SixGe0.4-xN and found that the starting temperature of NTE operation-temperature window shift toward low temperature. However, the width of NTE operation-temperature window was maintained after Si doping. The magnetic properties of Mn3Zn0.6SixGe0.4-xN were also measured by the physical property measurement system (PPMS), which shown that the paramagnetic (PM) to antiferromagnetic (AFM) transition around 370K disappeared after Si doping. This result coincide well with the low-temperature shift of NTE operation-temperature window, demonstrating the close correlations between NTE property and magnetic transition. Additionally, the spin-glass and ferromagnetic states occurred at low temperatures in Mn3Zn0.6Ge0.4N after Si doping.