In this paper a new method that based on state space estimation method is proposed to make joint estimation of the three parameters of range, velocity and angle for multi targets. According to the signal model of wideband array radar, we derived the Cramer-Rao Low Bound(CRLB) of these parameters, via constructing generalized Hankel matrix，we extend the sate space method into three dimension parameters. Numerical simulations show that the proposed method is an efficient method to estimate these parameters, which can uniformly approach to the CRLB. Meanwhile, compared to convention IFFT method, the proposed State-Space(SS) method gain better estimation and resolution property.