Abstract: Turbidity is of great significance for evaluating water quality. Addressing the issue of large measurement errors and low resolution encountered with the 90° scattering method in high turbidity scenarios, an advanced turbidity measurement technique utilizing 135° scattering was introduced, suitable for a wide range of turbidity. Since the scattering phase function was closely related to the scattering angle, the turbidity measurement adaptability of the scattering angle was studied by experiment. The analysis, conducted through polynomial fitting order, revealed that the 135° scattering method demonstrated a more extensive measurement range, particularly effective in the 100 NTU~2 000 NTU range. The method underwent rigorous experimental calibration, yielding segmented linear fitting R^2 results of 0.99 for 100 NTU~800 NTU, 0.98 for 800 NTU~1 500 NTU, and 0.99 for 1 500 NTU~2 000 NTU. Experimental results show that the 135° scattering approach can extend the turbidity measurement range and improve the precision of measurements in high-turbidity conditions.