Intravascular photoacoustic(IVPA) imaging combines photoacoustic imaging and medical endoscopic technique. It provides reliable information on cardiac vessels and atherosclerotic plaques for the detection of vulnerable plaques and interventional treatment of cardiac diseases. A method of reconstructing cross-sectional gray-scale images based on the time-reversal algorithm is proposed for the IVPA imaging system equipped with a single ultrasonic detector with circular scanning. The back-propagation of photoacoustic waves generated by the vascular tissues is modeled and numerically simulated to obtain 2D images of photoacoustic pressure distribution. The photoacoustic signals collected by the ultrasonic detector are interpolated to solve the problem of incomplete photoacoustic data caused by sparse measuring positions and limited-view measurement. The results of computer-simulated experiments suggest that the structural similarity of the reconstructed images is at least 65% higher than that of images obtained with the filtered back-projection algorithm. The proposed method can effectively improve the quality of the reconstructed image for IVPA imaging and can serve as a useful reference for subsequent optimization of image reconstruction algorithms.