Along with the continuous advancement of ecological civilization construction, the number and type of related cases are increasing, and accordingly, the scenarios on the identification and application of ecological environment service function loss are also increasingly showing a diversified trend, expanding from the traditional field of environmental pollution and ecological damage to the identification of wildlife resources and their ecological service function loss, the price of various functions of forest ecosystems, the calculation of attorney's risk agency fees, the confirmation of the amount of punitive damages for ecological damage, regulation of the implementation of ecological damage restoration and other contexts. This has led to the technical issue of how to correctly identify and recognize the loss of ecological environment service functions. Comparative analysis of the trial practice reveals that different courts often act in their own ways in the adoption and selection of judgmental methods: either applying the virtual cost of governance method for assessment, or treating it as ecological environment restoration costs directly, or separately and independently assessing the loss of ecological environment service function for double compensation; both pecuniary compensation and apologizing for damages, and even subscription to carbon sinks; applying both to environmental pollution and ecological damage. Due to the lack of clear legal provisions, there is a lack of unified understanding, and judges mostly make decisions based on ecological damage appraisal reports, which makes judicial discretion a mere formality. In order to solve the problem of confusing identification and mechanical adjudication caused by the confusion of concepts, through comparative verification and introduction of existing knowledge, methods and systems in the field of ecology, the concept of ecological environment service function is clarified and its connotation is confirmed to be supportive, regulating, supplying and cultural services for human beings. The Recommended Methods for Appraisal and Assessment of Environmental Damage (Second Edition) is amended, in which the methods are listed in the order of their application, and the form of setting out the estimation methods corresponding to the loss of ecological environmental services and environmental remediation costs in sub-chapters is adopted. The criteria for calculating ecological environmental remediation costs to make an estimation on the basis of the degree of differentiation between the environmental elements and the polluting substances is unified. Differentiating between the type of damages and the objects, taking into account the subjective factors, the method of virtual remediation cost should be used to assess the cost of ecological remediation in a conditional manner. At the time of compiling the Ecological Environment Code, in the structure and content of the Code, in addition to integrating and optimizing the existing legal norms, we can consciously incorporate the relatively mature wisdom and scientific methods that have been formed in the field of ecology, and it is appropriate to turn them into corresponding legal expressions on the basis of maintaining conceptual homogeneity, so as to further promote the effective connection between technical norms and legal norms.