Antenna is one of the most important parts of wireless communication and detection system, whose functions, tasks, configuration and weight are highly required in the study of mobile and space communication fields. The integral performance of the system would be highly improved for that the conformal array antennas will be used widely in the future aircraft, mobile communication and sonar, etc., fields. WSF (Weighted Subspace Fitting) algorithm, a classical high resolution method（DOA）, is replanted into the cylindrical conformal array antenna through modeling its 3D steering vector in this paper. The estimation variance of WSF and CRB for cylindrical conformal array antenna are carefully derived, and finally the performance and effect of DOA of bearing estimation is analyzed via computer simulations. The estimation results are gradually reached CRB shown in the computer simulations with the increasing of SNR and elements in matrix.