Although a variety of ways have been implemented to prevent the corium from fusing through the reactor pressure vessel in a severe water reactor accident, it is difficult to avoid the release of radioactive fission products (FP) in the containment during core degradation. This paper aims to assess the capabilities of SPRUCE code for simulating the FP release in severe accident. SPRUCE is a severe accident analysis code developed by CGN (China General Nuclear Power Corporation). This paper provides the simulation of FP release in the international standard problem PHEBUS FPT1 using SPRUCE. In the process of comparing with the experimental results of FPT1, it is found that the release model used is generally conservative. To some extent, a good agreement is reached with the measured release for noble gas Xe and some high-volatile classes such as Cs, I and Te. The release given by SPRUCE for Ba and U also shows fairly good agreement with the experimental results of FPT1. This paper also presents sensitivity analyses that focus on key parameters such as grain size of UO2, Nusselt number and fuel temperature in the FP release model. In general, the FP release results of SPRUCE are in relatively satisfactory agreement with the experimental measurements of FPT1.