A method for component carrier allocation, characterized by comprising: determining a Frequency Domain Metric, FDM, of User Equipment, UE, in a cell as 1 + ∑ m ∈ C k r k, m t T − 1 R k t, wherein C k is a component carrier set allocated for UE k, R k ( t) is an average data transmission rate of the UE k before a time slot t, r k,m ( t) is an instantaneous data transmission rate that the UE k reaches on an allocated component carrier m in the time slot t, and T is a measuring window size of an average throughput of the cell; when it is determined that a component carrier which has a frequency exceeding a preset frequency threshold exists in component carriers which are available to be allocated currently in the cell, updating the FDM of the UE in the cell according to coverage of the component carrier which has a frequency exceeding the preset frequency threshold; and determining frequency domain priority for the UE according to a descending order of the updated FDM, and allocating the component carrier which has a frequency exceeding the preset frequency threshold for the UE in the cell according to the frequency domain priority for the UE, wherein updating the FDM of the UE in the cell according to the coverage of the component carrier which has a frequency exceeding the preset frequency threshold comprises: when a coverage radius of the component carrier which has a frequency exceeding the preset frequency threshold is greater than or equal to a preset threshold r 2, updating FDM of UE which has a distance longer than a preset threshold r 1 and shorter than the preset threshold r 2 from a base station to which the cell belongs to a× FDM 1, and updating FDM of UE which has a distance longer than or equal to the preset threshold r 2 from the base station to which the cell belongs to b× FDM 2, wherein FDM 1 and FDM 2 are the FDM of the UEs before update, a is greater than 1, and b is greater than a. determining a Frequency Domain Metric, FDM, of User Equipment, UE, in a cell as 1 + ∑ m ∈ C k r k, m t T − 1 R k t, wherein C k is a component carrier set allocated for UE k, R k ( t) is an average data transmission rate of the UE k before a time slot t, r k,m ( t) is an instantaneous data transmission rate that the UE k reaches on an allocated component carrier m in the time slot t, and T is a measuring window size of an average throughput of the cell; when it is determined that a component carrier which has a frequency exceeding a preset frequency threshold exists in component carriers which are available to be allocated currently in the cell, updating the FDM of the UE in the cell according to coverage of the component carrier which has a frequency exceeding the preset frequency threshold; and determining frequency domain priority for the UE according to a descending order of the updated FDM, and allocating the component carrier which has a frequency exceeding the preset frequency threshold for the UE in the cell according to the frequency domain priority for the UE, wherein updating the FDM of the UE in the cell according to the coverage of the component carrier which has a frequency exceeding the preset frequency threshold comprises: when a coverage radius of the component carrier which has a frequency exceeding the preset frequency threshold is greater than or equal to a preset threshold r 2, updating FDM of UE which has a distance longer than a preset threshold r 1 and shorter than the preset threshold r 2 from a base station to which the cell belongs to a× FDM 1, and updating FDM of UE which has a distance longer than or equal to the preset threshold r 2 from the base station to which the cell belongs to b× FDM 2, wherein FDM 1 and FDM 2 are the FDM of the UEs before update, a is greater than 1, and b is greater than a. when a coverage radius of the component carrier which has a frequency exceeding the preset frequency threshold is greater than or equal to a preset threshold r 2, updating FDM of UE which has a distance longer than a preset threshold r 1 and shorter than the preset threshold r 2 from a base station to which the cell belongs to a× FDM 1, and updating FDM of UE which has a distance longer than or equal to the preset threshold r 2 from the base station to which the cell belongs to b× FDM 2, wherein FDM 1 and FDM 2 are the FDM of the UEs before update, a is greater than 1, and b is greater than a.