This paper discusses a numerical method for solving a first-kind Volterra integral equations system. Because of the ill-posedness of these equations, we need to apply an efficient computational method to discrete them to the system of algebraic equations. An expansion method known as the Chebyshev collocation method, based on the Chebyshev polynomials of the third kind, is employed to convert the system of integral equations to the linear algebraic system of equations. By solving the algebraic system, we conclude an approximate solution. Some numerical results support the accuracy and efficiency of the stated method.