The spatial light modulator (SLM) has narrow wavelength range and low diffraction efficiency, and limits the research of high-quality helical beams. Based on this, an effective SLM optimization method is proposed to greatly enhance the quality of helical beams produced by SLM. A laser with 650 nm wavelength is used as an example to produce the helical beams with different orbital angular momentums. The intensity distribution and diffraction efficiency of the generated helical beams are analyzed, and the experimental analysis proves the effectiveness of the proposed optimization method.