The cylindrical radial composite piezoelectric ceramic transducer is presented and studied. The transducer consists of an inner radially polarized piezoelectric ceramic thin-walled circular tube and an outer metal thin-walled cylindrical shell which are composed in the radial direction. The radial vibrations of a metal thin-walled cylindrical shell and a piezoelectric ceramic thin-walled circular tube are analyzed. Their radial electro-mechanical equivalent circuits are obtained. Based on the equivalent circuits and the radial boundary conditions, the composite electro-mechanical equivalent circuit of a cylindrical radial composite piezoelectric ceramic transducer is obtained, the resonance frequency and anti-resonance frequency equations of the cylindrical radial composite piezoelectric transducer are derived. Then the relationship between the resonance frequency, the anti-resonance frequency, the effective electromechanical coupling coefficient and the geometrical dimensions of the cylindrical radial composite piezoelectric ceramic transducer is analyzed. It is illustrated that the resonance frequencies and the anti-resonance frequencies from the frequency equations are in a good agreement with that of the experimental results.