A resource policy decision method in a roaming scenario, comprising: after having received an available resource query message from a mobility management and control function MMCF entity, a resource and admission control function RACF entity of a visited network acquiring degrade information of current service of a user from a resource and admission control platform, and according to a candidate access network list in the available resource query message, checking current availability of resource of each candidate access network in the candidate access network list, so as to obtain resource availability information of each candidate access network; the RACF entity of the visited network carrying out resource decision according to the degrade information, the resource availability information and user information of the user, characterized in that the degrade information comprises a parameter indicating whether or not already degraded, and the parameter indicating whether or not already degraded is used for indicating whether the current service of the user has been degraded, wherein the step of the RACF entity of the visited network carrying out resource decision according to the degrade information, the resource availability information and user information of the user comprises: if it is determined according to the degrade information that the current service of the user has been degraded, then in addition to choosing the candidate access network with the available resources meeting demand of the current service of the user, further choosing the candidate access network with the available resources meeting demand of the original resource information of the service of the user; and/or if it is determined according to the degrade information that the current service of the user has not been degraded, then in addition to choosing the candidate access network with the available resources meeting the demand of the current service of the user, in case when the current service of the user allows degradation, further choosing the candidate access network with the available resources meeting the demand of the degraded service of the user. after having received an available resource query message from a mobility management and control function MMCF entity, a resource and admission control function RACF entity of a visited network acquiring degrade information of current service of a user from a resource and admission control platform, and according to a candidate access network list in the available resource query message, checking current availability of resource of each candidate access network in the candidate access network list, so as to obtain resource availability information of each candidate access network; the RACF entity of the visited network carrying out resource decision according to the degrade information, the resource availability information and user information of the user, characterized in that the degrade information comprises a parameter indicating whether or not already degraded, and the parameter indicating whether or not already degraded is used for indicating whether the current service of the user has been degraded, wherein the step of the RACF entity of the visited network carrying out resource decision according to the degrade information, the resource availability information and user information of the user comprises: if it is determined according to the degrade information that the current service of the user has been degraded, then in addition to choosing the candidate access network with the available resources meeting demand of the current service of the user, further choosing the candidate access network with the available resources meeting demand of the original resource information of the service of the user; and/or if it is determined according to the degrade information that the current service of the user has not been degraded, then in addition to choosing the candidate access network with the available resources meeting the demand of the current service of the user, in case when the current service of the user allows degradation, further choosing the candidate access network with the available resources meeting the demand of the degraded service of the user. if it is determined according to the degrade information that the current service of the user has been degraded, then in addition to choosing the candidate access network with the available resources meeting demand of the current service of the user, further choosing the candidate access network with the available resources meeting demand of the original resource information of the service of the user; and/or if it is determined according to the degrade information that the current service of the user has not been degraded, then in addition to choosing the candidate access network with the available resources meeting the demand of the current service of the user, in case when the current service of the user allows degradation, further choosing the candidate access network with the available resources meeting the demand of the degraded service of the user.