A method for checking a field replaceable unit, comprising: obtaining first key identifier information saved in a security memory module; and determining trustworthiness of the field replaceable unit according to the first key identifier information saved in the security memory module and second key identifier information obtained from the field replaceable unit; wherein the determining the trustworthiness of the field replaceable unit according to the first key identifier information saved in the security memory module and the second key identifier information obtained from the field replaceable unit comprises: comparing the first key identifier information saved in the security memory module with the second key identifier information obtained from the field replaceable unit; if the first key identifier information saved in the security memory module is consistent with the second key identifier information obtained from the field replaceable unit, determining that the field replaceable unit is trustworthy; and if the first key identifier information saved in the security memory module is inconsistent with the second key identifier information obtained from the field replaceable unit, determining that the field replaceable unit is untrustworthy; characterized in that, the first key identifier information saved in the security memory module comprises an encrypted digest, the digest being a digest of an identifier and topology of a key chip in the field replaceable unit, wherein the topology of the key chip is a connection information of a Joint Test Action Group, JTAG, scan chain. obtaining first key identifier information saved in a security memory module; and determining trustworthiness of the field replaceable unit according to the first key identifier information saved in the security memory module and second key identifier information obtained from the field replaceable unit; wherein the determining the trustworthiness of the field replaceable unit according to the first key identifier information saved in the security memory module and the second key identifier information obtained from the field replaceable unit comprises: comparing the first key identifier information saved in the security memory module with the second key identifier information obtained from the field replaceable unit; if the first key identifier information saved in the security memory module is consistent with the second key identifier information obtained from the field replaceable unit, determining that the field replaceable unit is trustworthy; and if the first key identifier information saved in the security memory module is inconsistent with the second key identifier information obtained from the field replaceable unit, determining that the field replaceable unit is untrustworthy; characterized in that, the first key identifier information saved in the security memory module comprises an encrypted digest, the digest being a digest of an identifier and topology of a key chip in the field replaceable unit, wherein the topology of the key chip is a connection information of a Joint Test Action Group, JTAG, scan chain. comparing the first key identifier information saved in the security memory module with the second key identifier information obtained from the field replaceable unit; if the first key identifier information saved in the security memory module is consistent with the second key identifier information obtained from the field replaceable unit, determining that the field replaceable unit is trustworthy; and if the first key identifier information saved in the security memory module is inconsistent with the second key identifier information obtained from the field replaceable unit, determining that the field replaceable unit is untrustworthy; the first key identifier information saved in the security memory module comprises an encrypted digest, the digest being a digest of an identifier and topology of a key chip in the field replaceable unit, wherein the topology of the key chip is a connection information of a Joint Test Action Group, JTAG, scan chain.