A method and an apparatus for sending key-value pair data are provided, and a method and an apparatus for collecting key-value pair data are provided. In the method, first target key-value pair data is perturbed as first perturbed key-value pair data, so that a data collector can determine, based on a value a or b of a first value in the first perturbed key-value pair data, whether to include the entire first perturbed key-value pair data into the statistical result in a process of generating the statistical result. In this way, an association between a value and a key in the key-value pair data is reserved in the first perturbed key-value pair data, which improves availability of the first perturbed key-value pair data. That is, a statistical result generated by the data collector based on the first perturbed key-value pair data is closer to a statistical result generated based on original user key-value pair data.