Abstract: For the targets of conserving resources, protecting ecological environment and achieving a green and sustainable development of rare earth industry, an evaluation model of ion-adsorption rare earth mining technology was established from a new perspective of observability and controllability of modern control theory. The approaches of CRITIC-G1 combination weighting and cloud model were integrated in the research. The in-situ leaching technology and heap leaching technology under uncertain mining conditions were evaluated. The results show: ① By taking the impact degree and the controllability evaluation indexes of negative externality into consideration, the evaluation index system of ion-adsorption rare earth mining technology can be relevant to the actual mining conditions. ② The CRITIC-G1 combination weighting method renders an accurate index weight. ③ On the basis of CRITIC-G1 Combinational Weighting-Cloud Model, the heap leaching process is more favorable to in-situ leaching process under the uncertain mining conditions of resource reserves and ore deposit floor. In the meantime, the Environmental Protection Law and the Mineral Resources Law are strictly enforced. Under the current mining technology level, it is recommended to implement a reserve system for ionic rare earth minerals.