The purpose of this paper is to simplify the "double evaluations" mechanism and evaluation process, build an index system with karst characteristics from the perspective of ecological civilization to identify the advantages and disadvantages of the local resource background, and depict the characteristics of the spatial pattern more accurately. The evaluation index system was constructed from three perspectives including ecology, agriculture and construction. And we integrated the "barrel short board effect", weighted linear summation and multi-factor spatial overlap analysis to calculate the suitability degree of different functions in Ningyuan. The results show that the importance of ecological protection in the study area is relatively high, and the characteristics of spatial agglomeration and differentiation are obvious. The suitability of agricultural production is generally low. The areas suitable for production mainly take the central dividing line of the city as the axis belt, which shows a symmetrical distribution pattern on the east and west sides. On the whole, the suitability of construction and development is low, and the distribution pattern is remarkable. The pattern of land development and protection of "three-ring belts radiating" is obvious, and the construction-agriculture-ecological space is distributed in concentric circles. Areas of multiple, double, single and inappropriate spaces are 36672.67 hm2, 32276.11 hm2, 181022 hm2 and 175.46 hm2, accounting for 14.66%, 12.90%, 72.37% and 0.07%, respectively. The conclusion is that Ningyuan has good natural conditions, but it still needs to strengthen the protection of ecological space in the south and north to meet the requirements of ecological civilization construction. There are some conflicts between agricultural production and ecological protection space, so it is necessary to rationally optimize the structure and distribution of agricultural production to ensure the "double security" of regional food and ecology. There is less space suitable for construction and development, so we need to use land resources intensively, adjust and change the mode of development properly, and coordinate the relationship between "three living spaces". Double- and multi-suitable land for ecological construction is the key goal of the future development and protection pattern. This will give us a better understanding of the base of land space, and improve the scientificity and operability, which can provide reference and scientific support for the "double evaluations" work in ecologically fragile and sensitive areas, such as Southwest China.