Abstract: With the continuous development of mineral resources，goaf treatment has become the key to the prevention and control of goaf disasters，and the factors affecting its risk are many and complex，some of which are fuzzy. At present，many theoretical and technical achievements have been made in the evaluation of goaf safety， but most of the studies have not been carried out from the perspective of coordinated exploitation of resources.Therefore， under the principle of economy，safety and efficiency，aiming at the complexity and risk characteristics of goaf， based on the concept of “synergetic mining”，a relative membership model is established to evaluate the risk of goaf in the early stage，so as to provide reliable reference for synergetic management of goaf in the later stage.The burial depth of the mined-out area，span height ratio，groundwater，peripheral disturbance，gob span，structure of surrounding rock，RQD rock quality index，goaf area and ore pillar layout dimensions are selected as the characteristic parameters，and based on the theory of fuzzy mathematics，the relative membership degree matrix is built.Taking a mining area of Guangdong Province as the study background，the gob risk evaluation model is established.According to the theoretical calculaiton of the characteristics of the evaluation level，the goaf risk assessment is carried out.The evaluation results show that No.2，No.3，No.5 and No.6 goafs are the most dangerous ones，which is consistent with the actual situation of the mine.Based on the evaluaiton results，the synergetic preliminary prediction on the risk of goaf can be done effectively so as to reduce the management cost and safety risk degree of goaf.At the same time，the relative membership evaluation model is applied to make the evaluation factors have comparability，and the fuzzy recognition model has certain mathematical and physical significance.

Key words: Goaf risk, Relative membership, Fuzzy mathematics, Safety evaluation, Synergetic mining