Abstract: The situation awareness (SA) of smart distribution network (SDN) is a vital guarantee for the observability improvement and stable operation of SDN. However, due to the great difference of scenes and the lack of appropriate quantitative analysis method of the SA implementation effectiveness, SA is often difficult to meet the actual application requirements of rapidly responding to emergencies in SDN. We analyze the meaning, framework, and key technologies of SA in SDN and the effectiveness evaluation from the perspective of efficient operation. Firstly, the connotation, framework, and challenges of SA in SDN are introduced. Secondly, the key technologies of SA in SDN in the three stages of situation perception, situation assessment, and situation prediction are explained from the perspective of meticulous operation of SDN. Finally, to achieve a scientific evaluation of SA effectiveness of SDN, considering the quality of the SDN operation data and the ambiguity of subjective and objective evaluation, we describe the key technical content and development trend of the implementation effectiveness evaluation of SA in SDN from the indicator system and the weighting method, and analyze the framework and concept of self-learning evaluation technology. It is expected to provide specific criteria for the promotion and application of SA in SDN, and provide strong technical support for intelligent control of SDN.