A scanning method and device are provided. The method includes: determining values for a first scanning dosage and a second scanning dosage used in a scanning process based on a trigger condition which varies regularly and attenuation fluctuations of an object to be scanned, wherein the first scanning dosage is higher than the second scanning dosage, and at least one of the first scanning dosage and the second scanning dosage has an inconstant value and scanning a target position with the determined values. In the present disclosure, a scanning dosage may be reduced and different image noises may be kept consistent.