This paper investigates the robust beamforming design problem in a sensing assisted integrated communication and jamming (ICAJ) system, which aims to minimize the transmission energy consumption in a time duration while ensuring the communication requirements for multiple legitimate users and jamming demands for the suspicious network with multiple communication groups. To achieve these goals, we first design a sensing-communication and jamming (SCJ) protocol. Then, a robust beamforming design problem with both communication and jamming channel state information (CSI) estimation error is formulated as a non-convex optimization. To solve it, a joint optimization (JO) algorithm is developed to jointly optimize the beamforming matrices of communication and jamming, by leveraging the General S-procedure, Schur' complement and General Sign-definiteness techniques. Simulation results show that the proposed SCJ protocol with JO algorithm has superior performance, as compared to benchmark methods.