The invention relates to 
optical communication field, discloses a collating device and method for dynamic bandwidth in source-free optical network, and the 
distribution method for dynamic bandwidth is transparent, which can satisfy the requirement for different service, improve the 
utilization rate of bandwidth, realize the 
fair distribution for bandwidth, good haleness, real time, and can distribute bandwidth for different port, and support to release offline bandwidth of ONU. The distributing device for dynamic bandwidth in source-free optical network includes ascending service active 
fiber network unit bit-mapping register, ascending service active port bit-mapping table, ascending virtual media accessing control sub-layer information table, descending virtual media accessing control sub-layer 
authorization information table; said distributing device for dynamic bandwidth, consults said 
fiber network unit active information, port active information and length information of sending data, according to preset priority of different service, process the 
service flow according to priority according to preset priority, and distributes the dynamic bandwidth for ports.