In atmospheric wireless optical communication, the droplets in atmosphere may cause laser signals to attenuate severely, thus resulting in the attenuation of the temporal spread and energy of pulse signals. A Monte Carlo method is used to simulate the transmission of 1.064 μm laser pulses in fog. In the simulation, the scattering phase function values of light in the fog with different visibility are calculated according to the Mie scattering theory. The corresponding relation between the random number and the scattering angle is obtained through random sampling. Compared with the method in which the H-G phase function is used to represent the Mie scattering characteristics of particles to light approximately, this method is more accurate. On this basis, the impulse response characteristics of laser signals at different receiving view angles under different fog environment are simulated.