Hydraulic fracture test is one of the most commonly used measurement methods to obtain in situ crustal stress, which is important information for the earthquake risk assessment and geological resources development evaluation. However, the variation of injected water pressure during a hydraulic fracture test is affected not only by principal stress components to be measured, but also by properties of rock formation such as strength and homogeneity. The scattered measurement results from various hydraulic fracture tests carried out nearby typically generate difficulties in the interpretation of in situ stress. Our study develops a three-dimensional particle flow code for the simulation of hydraulic fracture tests. Rock strength is considered through bonding properties between particles, and the heterogeneities of rock formation can be taken into consideration through varying bonding properties. The injected water seeps through particles and the associated injected pressure accumulated within the spaces surrounding by particles. Simulation results demonstrate that our code is capable of reproducing the characteristics of a pressure curve obtained by a hydraulic fracture test and the development of rock fractures can be compared simultaneously, benefiting the interpretation of measured results and associated explanation regarding scattered results caused by rock heterogeneity later on.