In this work, the finite difference time domain (FDTD) method has been utilized to simulate the propagation emission from PbS quantum dots in a hexagonal InP nanowire as a single photon source. The effect of height and radius of the nanowire as well as the location and orientation of the dipole source in the Purcell factor and Quality factor of the nanowire have been investigated. A broadband electric dipole source has been used to model the quantum dot and the effect of shape and radius of PbS quantum dot have been investigated in the final results. The conclusive structure has been optimized to a nanowire with hexagonal cross section with radius of 220nm and height of 10um. The emission peak obtained above 1um with Purcell factor of 4.72 which is in good agreement with cases have been used as single photon source in quantum communication.