To accurately and effectively calculate and evaluate photon doses under different radiation conditions by selecting appropriate calculation methods, this paper compares and studies four commonly used photon dose calculation methods in Monte Carlo simulation software: dose conversion coefficient method, heat number method, track length energy deposition method and pulse height method. Starting from the calculation principle and combining simulation results, these four methods are analyzed and compared. By simulating single energy photon beams with different energies incident on water spheres of different volume sizes, the error caused by approximating absorbed dose with kerma was analyzed, and the influence of different contents of high atomic number element gadolinium on absorbed dose calculation results was simulated and analyzed. Due to the fact that the conversion coefficient is calculated based on the reference human model, the dose conversion coefficient method can only quickly estimate and calculate the absorbed dose, it is difficult to obtain accurate dose in specific situations. When high-energy photons are incident on a small volume of material, kerma will be greater than the absorbed dose, thus the heat number method and the track length energy deposition method will produce errors, and the pulse height counting method is more suitable. At low energy and large volume, any method can be selected based on computational accuracy and computer resources. When the content of high atomic number elements in a substance increases, the calculation error between the track length energy deposition method and the pulse height method will decrease.