The invention discloses a multichannel magnetic sensor detection and data collection circuit which comprises a sensor array, a data collection circuit and a voltage conversion circuit. The sensor array converts a magnetic field into analog voltage signals and filters the analog voltage signals, the data collection circuit converts sensor analog voltage signals into digital quantity and serially transmits the digital quantity to a magnetic leakage detection data recording system, and the voltage conversion circuit converts a power supply source into an analog power source, a digital power source and reference voltage that the sensor array and the data collection circuit need. The multichannel magnetic sensor detection and data collection circuit realizes high-density integration of multiple sensors, transmission cables for the sensors are reduced, and objective needs on miniaturization of a magnetic leakage inside detector are met.