Markable on-line strip surface defect detection system

The invention discloses a markable on-line strip surface defect detection system. The markable on-line strip surface defect detection system comprises a surface defect capturing device (10), a computer system (50), a server (30) and a control console (20), wherein the surface defect capturing device (10) comprises a video camera (11), an illuminating apparatus (12) and a spraying device (14); the spraying device (14) is connected with the video camera (11). An image captured by the video camera is input to the computer system, and is processing by the computer system, so as to obtain analysis results; the analysis results are input to the server, the server analyzes and compares the analysis results to obtain the comprehensive evaluation to the surface quality of a strip, if the strip has a defect, the control console connected with the server drives the spraying device to spray the surface of the strip, so that the specific location of the defect can be marked, the further field study on the defect can be conveniently performed by workers so as to enable the quality of the strip to be controlled and improved.