A wide range of application has made high-voltage (HV) MOSFETs evolve into application-specific structures. Trench-gate type HV-MOSFET is one of them; its user application space tends to fall on a larger power consumption domain, compared with planar HV-MOSFET. As for planar HV-MOSFETs, regardless of DDMOS or LDMOS, HiSIM_HV has begun to serve design community as a world recognized model. In this work, the benefit of HiSIM_HV would be extended to another class of HV device, i.e., trench-gate type HV-MOSFET, while the framework of the HiSIM_HV model formulation is kept intact as much as possible. The modified code successfully can play back TCAD-generated measurement data.