The invention provides an AMOLED external electrical compensation detection method. The method comprises the steps that under a display mode, the cross voltage between a drain electrode and a source electrode of a detection thin film transistor is estimated firstly, then the estimated value of the cross voltage between the drain electrode and the source electrode of the detection thin film transistor is used for calculating a grid source electrode voltage of a drive thin film transistor, and the writing precision of the grid source electrode voltage of the drive thin film transistor can be improved; under a detection mode, the cross voltage between the drain electrode and the source electrode of the detection thin film transistor is estimated firstly, then the estimated value of the cross voltage between the drain electrode and the source electrode of the detection thin film transistor is used for calculating the voltage of a source electrode of the drive thin film transistor, and the calculated voltage of the source electrode of the drive thin film transistor is used for calculating the threshold voltage and the carrier mobility of the drive thin film transistor. The AMOLED external electrical compensation detection method can reduce calculation errors of the threshold voltage and the carrier mobility of the drive thin film transistor and improve the precision of AMOLED external electrical compensation detection.