The invention provides a label detection method and device for a label printer. The paper outlet of the label printer is provided with a paper taking sensor, and the paper taking sensor comprises a light generator and a light receiver. The method comprises the following steps of conveying the printed label to a preset position of the paper outlet; periodically controlling the light generator to bepowered on and powered off in sequence, acquiring the power-on output value of the light receiver when the light generator is powered on and the power-off output value of the light receiver when thelight generator is powered off in each period; according to the power-on output value, the power-off output value and the detection threshold value of the light receiver in each period, determining whether the label is taken away in the period. The label detection method and device for the label printer can solve the problem that the label printer in the prior art is inaccurate in detecting whether the label is taken away from the paper outlet due to the outside light interference.