Cast-in-place pile concrete interface monitoring device and monitoring method

The invention discloses a cast-in-place pile concrete interface monitoring device which comprises a display unit and a plurality of detection units. The plurality of detection units are sequentially arranged from bottom to top from the lower end opening of a concrete conveying guide pipe and are distributed on the outer wall of the concrete conveying guide pipe at equal intervals in the vertical direction. The plurality of detection units are respectively connected with the display unit in a wired connection or wireless connection mode, convert detected information into analog values and transmit the analog values to the display unit. A coordinate graph is formed by taking the corresponding setting sequence of the detection units as an abscissa and the unit value of the detected information as an ordinate, and the corresponding analog numerical values detected by the detection units are arranged one by one and sequentially connected into a linear graph for display. The invention also provides a monitoring met