Objective To compare the filling effect of SonicFill sound-dynamic resin seal filling and traditional composite resin filling in class Ⅰ cavity of posterior teeth. Methods A total of 120 patients with class Ⅰ cavity of posterior teeth who were treated in Hefei Stomatological Hospital from January 2023 to June 2023 were selected as the research objects. They were divided into control group and experimental group by random number table method, with 60 patients in each group. The control group was filled with Filtek Z350 XT general resin, and the experimental group was filled with SonicFill sound-dynamic resin seal method. The filling time, jaw adjustment times and aesthetic filling efficiency were compared between the two groups. Results The filling time of the experimental group was (236.75±36.52) s, which was shorter than (278.26±34.05) s of the control group (P <0.05). The number of jaw adjustments in the experimental group was 1.00(1.00,2.00), which was less than 2.00(2.00,2.80) in the control group (P <0.05). The aesthetic filling efficiency of the experimental group was 88.33%, which was higher than 80.00% of the control group (P <0.05). Conclusion SonicFill sound-dynamic resin seal filling treatment can shorten the operation time of class Ⅰ cavity caries in posterior teeth, reduce the number of jaw adjustment, and improve the efficiency of aesthetic filling.