The temperature field of fractured rock mass in the multi-coupling field is a hot topic. The temperature field and outlet temperature of fractured rock mass were calculated under different fractured parameters by 3DEC program based on the conceptual model of fractured rock mass, and the results showed that the same inlet temperature of the fracture has a weak influence on the temperature field of the rock mass. The temperature field of rock mass is dominated by the high fractures intake temperature, and the time required for the model to reach steady state is slightly affected by the intake temperature of fractures. The higher the water flow velocity and opening of the fracture, the higher the temperature of the rock mass of the same height. The reduction of the water flow velocity and the opening of the end fracture extend the time required for the model to reach steady state. The parameters of the two end fractures play a leading role in the temperature field of rock mass due to the marginal effect, and the influence on rock mass temperature field from high to low ranks: fracture water temperature > water flow velocity > fracture opening.