Prospective, randomized, parallel-controlled trial. The primary aim of this study was to determine whether hrombin-gelatin matrix (TGM) combined with an absorbable gelatin sponge (AGS) could more greatly reduce Intraoperative blood loss (IBL) in unilateral open-door laminoplasty than the sole use of an AGS could. The secondary aims were to evaluate the hemostatic efficiency, amount of postoperative bleeding and safety of the application of TGM combined with an AGS. IBL during cervical laminoplasty is substantial and is a proper indication for the application of hemostatic agents. However, we are unaware of any clinical trials on the application of TGM and an AGS in posterior cervical spine surgery. A total of 80 consecutive patients who underwent unilateral open-door laminoplasty, were enrolled from September 2020 to March 2022. Patients were randomized into two groups, the TGM-AGS group and the AGS group, with 40 patients in each group. The primary outcome was IBL. Other outcomes included the duration of operation, duration of hemostasis, duration of drainage, maximum decrease in hemoglobin(Hb), length of hospital stay, volume of drainage, number of drainage days, occurrence of adverse events, coagulation indicators and patient-reported outcome measures (PROMs). The mean IBL for patients in the TGM-AGS group (75.22mL ±21.83mL) was significantly lower than that in the AGS group(252.43mL ±57.39mL)(mean difference=177.21mL, 95% confidence interval [CI], 157.88mL -196.53mL, t=18.25, P<0.001); the duration of hemostasis, volume of drainage, days of drainage in the TGM group and maximum decrease in Hb were also significantly less than those in the AGS group (P<0.01). The hemostatic efficacy of TGM-AGS is better than that of an AGS alone in IBL. TGM-AGS is also superior to an AGS alone in the evaluation of hemostatic efficiency and postoperative bleeding.