Objective To analyze the effect of full crown restoration combined with root canal therapy on affected tooth function recovery in patients with cracked tooth complicated by chronic pulpitis. Methods A total of 60 patients (60 affected teeth) with cracked tooth complicated by chronic pulpitis who visited the Department of Stomatology of our hospital from January 2022 to January 2023 were selected, and they were divided into the control group (n=30) and the observation group (n=30) by the random number table method. The control group was treated with root canal therapy alone, and the observation group was treated with full crown restoration on the basis of the control group. The clinical efffcacy, pain intensity, affected tooth function recovery, tooth preservation rate and complication rate were compared between the two groups. Results The total effective rate of the observation group was 96.67%, which was higher than 73.33% of the control group (P<0.05). The VAS scores of the observation group at 1, 6, 12 and 24 months after treatment were lower than those of the control group (P<0.05). The masticatory function, occlusal stability and aesthetic satisfaction of the observation group were higher than those of the control group (P<0.05). The tooth preservation rate of the observation group was 93.33%, which was higher than 70.00% of the control group (P<0.05). The incidence of complications in the observation group was 3.33%, which was lower than 20.00% in the control group (P<0.05). Conclusion Full crown restoration combined with root canal therapy for cracked tooth complicated by chronic pulpitis can effectively relieve pain, improve patients' masticatory function of the affected tooth, occlusal stability and aesthetic satisfaction, reduce the incidence of complications, and improve the long-term preservation rate of the affected tooth.