A built-in interdental brush, comprising an interdental brush , a camera system (25-2), a lighting system , and a delivery component , wherein the interdental brush is movably built in a bended tube (21-1) of a front end of the delivery component , wherein: A: the delivery component comprises a guide head , a sliding mechanism , and a housing , wherein the guide head is disposed on the front end (2-1) of the delivery component , and the guide head comprises the bended tube (21-1), and an outlet (21-2) of the bended tube (21-1) is disposed at an end (21-3) of the guide head ; B: the interdental brush comprises a working part with fiber or a protrusion (11-1) and a connector , wherein the working part is disposed at a front end of the connector ; and C: the camera system (25-2) is configured to enable observation of a working state of the interdental brush and oral cavities of a user during cleaning, and includes a camera (25-2-1) the guide head at the front end of the delivery component (2-1), and a data processing and outputting system (25-2-2) and an electrical system ; D: the lighting system comprises a light source system (24-1) configured to provide lighting to the camera (25-2-1); and E: the interdental brush is installed in the bended tube (21-1), the working part of the interdental brush can slide in the bended tube (21-1), and the connector of the interdental brush is installed on the sliding mechanism of the delivery component ; a movement of the sliding mechanism can drive the working part of the interdental brush slide in the bended tube (21-1); and the sliding mechanism is driven to make the working part of the interdental brush extend from the outlet (21-2) of the bended tube at the end of the guide head. A: the delivery component comprises a guide head , a sliding mechanism , and a housing , wherein the guide head is disposed on the front end (2-1) of the delivery component , and the guide head comprises the bended tube (21-1), and an outlet (21-2) of the bended tube (21-1) is disposed at an end (21-3) of the guide head ; B: the interdental brush comprises a working part with fiber or a protrusion (11-1) and a connector , wherein the working part is disposed at a front end of the connector ; and C: the camera system (25-2) is configured to enable observation of a working state of the interdental brush and oral cavities of a user during cleaning, and includes a camera (25-2-1) the guide head at the front end of the delivery component (2-1), and a data processing and outputting system (25-2-2) and an electrical system ; D: the lighting system comprises a light source system (24-1) configured to provide lighting to the camera (25-2-1); and E: the interdental brush is installed in the bended tube (21-1), the working part of the interdental brush can slide in the bended tube (21-1), and the connector of the interdental brush is installed on the sliding mechanism of the delivery component ; a movement of the sliding mechanism can drive the working part of the interdental brush slide in the bended tube (21-1); and the sliding mechanism is driven to make the working part of the interdental brush extend from the outlet (21-2) of the bended tube at the end of the guide head. <EOS>