While predicting reservoir temperature numerically, flow field and pressure field were obtained and rectified orderly at each time step with a low efficiency in traditional SIMPLE algorithm procedure. According to the theory of SIMPLE pressure correction, this paper treated coefficients matrix preparing and governing equations resolving as well as velocity and scalar equations side by side and the parallel mechanism was applied to the laterally averaged 2-D reservoir water temperature model. The parallel result calculated on a Intel 4-core processor showed a good agreement with the serial and the parallelism improved the calculation performance efficiently with its speedup index reaching 1.5.
