The invention discloses an analysis early warning system based on the air pre-heater bypass sealing air speed for air pre-heater blocking detection. The analysis early warning system comprises an air speed measuring device, a signal transmission system, a DCS module and a computer. The output end of the air speed measuring device is connected with the input end of the signal transmission system, and the output end of the signal transmission system is connected with the computer through the DCS module. The air speed measuring device is fixedly arranged on an outer shell of an air pre-heater, a speed measuring end is arranged in bypass sealing space between the outer shell and an air pre-heater rotor, and the bypass sealing space is located on a primary air or secondary air side, away from a flue gas side, at a cold end of the air pre-heater. The analysis early warning system is sensitive to reaction, convenient to install and high in reliability, can timely reflect the air pre-heater blocking condition, is convenient for operating staff to strengthen soot blowing and for fuel staff to adjust fuels, makes pointed references for avoiding or relieving air pre-heater blocking, changes from passive to active, and guarantees safe and reliable operation of the air pre-heater.