The realistic simulation of underwater scenes has important significance for many researches related to underwater vision, such as underwater image restoration, underwater moving object monitoring, etc. To date, however, the existing underwater scene simulation pipelines are either too complicated due to the continuous spectra and camera parameters involved, or difficult to control since the empirically controlled distance based fog effect is usually used by them. In this paper, we try to fill in this research gap by proposing an Underwater Scene Simulation approach, namely USSim, which especially focuses on the influence of ocean water. In USSim, Jerlov water type and depth are regarded as main variables to control the simulation effects. In addition, the spectra of the incident light is decomposed into three primary components and their attenuations are modeled separately, and finally the simulated scene is generated via the hybrid underwater imaging model proposed by us. USSim greatly reduces the computational complexity and enables the fog effect to be controlled by variables with explicit physical meanings. The controllability, physical interpretability and simulation effects of our USSim under different conditions have been verified by extensive experiments. To make our results reproducible, the source code is made online available at https://cslinzhang.github.io/USSim/.