We investigate the short-range correlation effects of plasmon-phonon collective excitations in a quantum well wire by using the self-consistent field approximation theory proposed by Singwi, Tosi, Land and Sjolander [Phys. Rev. 176, 589 (1968)]. In our calculation model, we consider a three-subband model with only one populated, for a rectangular cross-section quantum well wire with infinite height for the potential barrier. We have verified that by decreasing the wire width (and/or decreasing the electronic density), the local field correction effects are increased. We compare the present results with those obtained within the Random Phase Approximation throughout the paper and found that the differences between the two calculation methods are more significant for the intrasubband plasmon.