Abstract: To ensure the detection quality of the domestic model ionospheric digisonde adopted by the Phase II of Chinese Meridian Project, prototype testing including technique testing and a data quality comparison was performed. The test was carried out in the National Space Weather Observation Station in Danzhou, Hainan. After the prototype digisonde testing process was introduced and completed, the data quality evaluation results were analyzed in detail. A thorough comparison demonstrated that the prototype reached the overall standard established by the mature-type DSP-4D in the aspects of quality of ionograms, accuracy of ionospheric parameters (h'F2, hmF2, foF2, auto-scaled or manual-scaled), and drift velocity. According to the testing results of technical indices, the peak power of the two transmitting channels is no more than 686 W, and the voltage standing wave ratio is no more than 2.23. The sensitivity of the receiving channel reached −125 dBm, and the dynamic range reached 105 dB. The baseband bandwidth of the digital receiver is 70 kHz, and the suppression of outband interference is no less than 101 dB. The results of the data quality evaluation showed that the average differences between the prototype digisonde parameters of Fof2, h'F2, and hmF2 obtained using auto-scaling and manual scaling are 0.02 MHz, 28.39 km, and 0.39 km, respectively. The average differences between the three parameters of the prototype digisonde and those of the DPS-4D obtained using auto-scaling are −0.0 MHz, −2.61 km, and −9.12 km, respectively. The average differences between the three parameters of the prototype digisonde and those of the DPS-4D obtained using manual scaling are −0.13 MHz, 14.7 km, and 3.21 km, respectively. The prototype testing clarified the status of the technique of the domestic instrument, greatly contributing to its design optimization and finalization. It also established a reference for digisonde data quality assessment.