All-coefficient golden section adaptive control scheme for attitude keeping of spacecraft with unknown parameters is proposed in this paper. Based on Lyapunov’s direct method for time-variant discrete systems, the paper gives the conditions for the uniform asymptotic stability of the all-coefficient golden section adaptive control system. The given conditions are dependent on the relations between coefficients in the closed-loop system equations and the variable rates of the coefficients. The result in this paper can be used to analyze quantitatively the stability of multivariable time-variant discrete systems. Thus, a theoretical foundation is established to apply the golden section adaptive control method to control specific spacecraft.