To estimate Doppler frequency and Direction-of-Arrival (DOA) accurately and efficiently, a joint spectrum estimation method based on Weighted Subspace Fitting (WSF) algorithm and Quantum-behaved Particle Swarm Optimization (QPSO) algorithm, namely WSF-QPSO, was presented. First, an extended observability matrix containing the information of Dopplers and DOAs was constructed by using a state-space model, and the joint spectrum function was fitted by using WSF algorithm. Then, the joint parameter estimation was converted to multidimensional nonlinear function optimization. Finally, the Dopplers and DOAs were estimated by optimizing the joint spectrum function using QPSO algorithm. Experimental results indicate that the Root Medium Square Errors (RMSEs) of Dopplers and DOAs estimated from the WSF-QPSO method are 0.007 5 rad and 0.25°, respectively when SNR is 0 dB. The proposed method can get high resolution and robust parameter estimation with less control terms, and the parameters are paired automatically. In addition, the WSF-QPSO method can obtain acceptable estimation results even under the condition of low SNR or small snapshot number in comparison with the joint spectrum estimation methods based on subspace decomposition.