A background correction method for CT scan data is provided. A background collection may be performed to collect a first background data set and background data before a CT scan. The CT scan may then be performed to collect one or more CT scan data sets, and status information for collecting each of the CT scan data sets. A second background collection may additionally be performed to collect a second background data set after the CT scan, and status information for collecting the second background data set may also be recorded. The first background data set, the second background data set and corresponding status information may then be used to obtain a background data set for collecting each of the CT scan data sets. The corresponding background data set may be removed from each of the CT scan data set to obtain a background-corrected CT scan data set.