In order to transform a Gaussian beam with uniform polarization into a vector beam with tunable polarization distribution, an optical method was proposed to generate vector beam and control the polarization distribution, based on the polarization characteristics of the S-wave plate and double retarders. Combined with the Stokes-Mueller matrix algorithm, a mathematical model of the polarization control of vector beam was established. And the polarization states distribution of the output beams were calculated, when a linear polarized Gaussian beam passed through the S-wave plate and the double retarders (including two situations: double quarter-wave plates and double half-wave plates). The relationship between the angle of the double retarders and the polarization distribution regular pattern of the output vector beam were discussed. The experimental results agree well with the numerical simulation results, which show that the method can achieve the complex polarization control for a scalar coherent beam, and the correctness of the theoretical analysis is verified.