The magnetic field in single-layer solenoid with multi-current is calculated using Elliptical function, Legendre polynomials and Biot-Savart law. The optimization conditions to a highly uniform magnetic field in the center of solenoid has been studied. The variation of magnetic field depending on radius difference was examined. The uniformity of magnetic field is compared with that obtained each multi-current method. The five-current method increases the working space within 0.02 ppm uniformity by eighty times that using single current method. And this method improves the magnetic field uniformity which is equivalent to the effect of 160 m long solenoid by using single current.