The invention relates to a manufacturing method of a valve part, and the method comprises the following steps: forging electroslag remelting ingot billets, cogging, polishing, finishing carrying out flaw detection and blanking; heating the billets to 1140-1160 DEG C, preserving heat again for 90 minutes, and carrying out upsetting, drawing down, upsetting, drawing down, chambering, billet separation, drawing down and rounding forming treatments on the billets; carrying out flaw detection on the obtained billets; and finally, carrying out solution treatment, air cooling stabilized treatment and age-hardening treatment on a sample. Compared with the prior art, the invention has the advantages that the eligibility of the billets is ensured, the risk brought by carrying out normal forging once is lowered, the inner and outer temperature difference of the billets is reduced, scrap caused by unreasonable heating is solved, the phenomena of centre burst and crack of a forging are avoided, the yield is improved, and the eligibility of the obtained forgings is more than 98%.