The invention provides a path evaluation method and a path evaluation device. The path evaluation method comprises the steps of: transmitting an analog data packet for simulating a predetermined service to a head node of a service forwarding path; acquiring traffic information of a port for transmitting the analog data packet on each switch in the service forwarding path; and evaluating the service forwarding path based on the traffic information. The path evaluation method and the path evaluation device can solve the problem that newly added traffic is about to impact the network quality after an SDN undergoes traffic planning in the related art, and achieve the effect of impacting the network quality by means of the newly added traffic.