The PPP time and frequency transfer method is a high-precision time and frequency transfer method for GNSS that has the characteristics of high precision, wide range, and low cost. The CV time and frequency transfer method can eliminate the satellite clock and reduce path errors, such as ionospheric and tropospheric errors. This study combines the advantages of the two methods and implements an improved PPP time and frequency transfer method. In the experiment, five IGS stations are connected to UTC( k) and one external high-precision hydrogen clock is selected to form zero, short, and long baseline links to evaluate the performance of the improved PPP. The results show that when IGS final clock products are used as time reference, the time transfer accuracy of the improved PPP is improved by 2. 55% ~17. 78% compared to PPP. The frequency stability can reach 2. 0×10 -17 / 600 000 s for the zero-baseline link. The short-term frequency stability is better than that of PPP when the common-view satellite does not change in the zero-baseline, and the long-term frequency stability is comparable to that of PPP. The frequency stability of the improved PPP of each link in the non-zero baseline link after the average time of 10 000 s is improved by about 10% compared with the IGS final products and the BIPM PPP.