The disclosure discloses a method for traffic limitation by a leaky bucket, including that: during traffic-limitation of a group of packets sharing a same leaky bucket and having separate weighted priorities, the overall leaky bucket is divided into multiple sub-buckets according to priority parameters of the packets including a number of the weighted priorities and ratios between the weighted priorities; after packet information is received, parameters relevant to traffic-limitation by a leaky bucket is acquired; a total number of tokens to be added to the overall leaky bucket is calculated; token-addition is performed on the sub-buckets according to a state of the overall leaky bucket after addition of the total number of tokens and the weighted priorities corresponding to the sub-buckets; a packet is forwarded, or discarded, or marked according to a length of the packet and a number of tokens in a sub-bucket corresponding to a weighted priority, wherein in performing token-addition on the sub-buckets, after token-addition is performed on all the sub-buckets, any overrunning token is allocated to another sub-bucket not overrun with tokens. The disclosure further discloses a device for traffic limitation by a leaky bucket. With the disclosure, it is possible to limit packet traffic flexibly according to weighted priorities and improve resource utilization.