Objective To evaluate the clinical effectiveness of modified resin-filled mixing knife on the attachment bonding of invisible appliance, so as to improve the efficiency and success rate of the attachment bonding. Methods Patients who were treated with invisible aligner in the Orthodontic Department were selected as the subjects and divided into two groups randomly with 800 attachments in each group. The experimental group used modified resin-filled mixing knife for attachment bonding, while the control group used traditional resin-filled mixing knife. The operation time and immediate success rate of all attachments were recorded. Results In the experimental group, the filling time of each attachment was (8.81±2.45) seconds, and the success rate of immediate bonding was 87.75%. In the control group, the filling time of each attachment was (12.22±3.70) seconds, and the success rate of instant bonding was 69.25%. There were statistically significant differences in the filling time and immediate success rate of each accessory between the two groups (P<0.05). Conclusion The use of modified resin-filled mixing knife can effectively shorten the filling time and improve the immediate bonding success rate of the attachment.