The work aims to design a PQP fast reading algorithm based on PWM duty cycle criterion, speed up the popularization and application of this information hiding and printing anti-counterfeiting method and solve the low accuracy and slow speed of PQP lattice data reading algorithm. First, the pulse width modulation (PWM) and the minimum duty cycle optimization method were adopted to estimate the grid angle of the acquired PQP image under non-correction conditions. Then, the maximum value sequence in the horizontal and vertical directions were calculated respectively based on the obtained grid angle with reference to the PQP dot matrix image. Next, the second difference and adaptive threshold judgment on the sequence were performed to draw the PQP dot matrix data reading grid. Finally, characteristic value of each position in the sequential index network pointed by the square spiral line was used to read the PQP dot matrix data information. Through simulation and experimental tests, when the printing resolution was 600 dpi, the reading time and bit error rate of PQP image information were controlled within 0.5 s and ±5%, respectively. The information extraction of PQP dot matrix image is realized under the uncertain conditions of uncorrected, unreferenced and blind synchronization information.