Abstract: The operating principle of voltage controlled single-inductor dual-output（SIDO） Buck converter in continue conduction mode was analyzed in this paper.The state space average model was established by utilizing the state space average algorithm to obtain the input-output open-loop transfer function structure and Jacobian matrix.Based on the transfer function and Jacobina matix,the Nyquist stability criterion and Routh-Hurwitz stability criterion were employed to analysis the system stability and stability boundaries of the converter with respect to various control parameters.Furthermore,the effect of capacitor parameters on control parameters stability region was studied.Research results show that the control parameters have a stable upper-boundary or lower-boundary; moreover,the different capacitors influence the stability operation range of the control parameters.Finally,simulation and experiment of voltage controlled SIDO Buck converter were established to verify the theoretical analysis.