Compared with the video compression standard High Efficiency Video Coding (HEVC), the latest standard Versatile Video Coding (VVC) has achieved great improvement in coding efficiency due to the application of more sophisticated coding tools, which also results in high coding complexity. In this paper, to reduce the computational complexity of dependent quantization in VVC, an optimization method based on theoretical analysis of rate-distortion performance and statistical low-complexity model establishment is proposed to delay the starting point of the quantized path. Experimental results demonstrate that the proposed method can postpone the starting point to a position closer to the last non-zero quantized coefficient, reducing 3.57% encoding time, with a 0.42% increase in Bjφntegaard delta bit-rate (BD-BR) compared with VVenC 1.0.0 under medium preset.