We propose an output error-driven random controlled Single Inductor Multiple Output (SIMO) buck/boost DC-DC converter operated in the Continuous Conduction Mode (CCM). Random selection of output switches based on maximum instantaneous output error enables us a novel control scheme which leads to a fast transient response with mitigating the cross-regulation problem of buck-boost converters. A freewheeling period for CCM control is not necessary in the proposed output error-driven control scheme thanks to the instantaneous control of output switches, hence, we can achieve high power conversion efficiency as well as stability of operation. Both simulated and experimental results show the effectiveness of the proposed control scheme. The measured power conversion efficiency of the converter with 3 buck/boost output nodes is approximately 91.0%.