Single-pixel imaging has made significant progress in imaging quality and speed. However， how to improve the imaging speed while ensuring the imaging quality is still a problem to be solved. Based on the finding that the average value of the absolute value of the Hadamard coefficients of each oblique line declines rapidly， an adaptive oblique zigzag sampling method is proposed to achieve the expected imaging speed and quality. Experimental results show that the number of sampling and the amount of data acquisition can be effectively reduced using the proposed method， improving the imaging speed while ensuring the imaging quality. Compared with the single-pixel imaging using sequential sampling， the imaging quality of the proposed method is better under the same sampling rate.