Aiming at the predicting difficulty of local convective precipitation in weak environmental field, two local convective precipitation cases in the lower Yangtze River region were took as examples, and YSU and ACM2 parameterization schemes in WRF model were selected to explore feasible way to improve this problem by adjusting the vertical mixing intensity in the boundary layer. The results show that the development of convection simulated by YSU scheme is relatively slow and the triggering of convection is slightly later under the default vertical mixing intensity, while the convection simulated by ACM2 scheme is weaker than that of YSU scheme, and the triggering of convection is about 1-2 hours later than the observation due to too strong vertical mixing. Reducing vertical mixing intensity could get more accurate convective triggering time and its evolution in YSU and ACM2 schemes. The vertical distribution of potential temperature, water vapor ratio and wind, the transport of energy are affected mainly by different vertical mixing intensity, so that get varies of simulation results. There is colder and wetter in the boundary layer, stronger wind speed and wind shear from surface to the top of the boundary layer in the early stage of the convection, and larger CAPE (Convective Available Potential Energy), all of them are conductive to trigger convection earlier, at the meanwhile, the intensity stronger.