The invention relates to the technical field of refrigeration equipment, in particular to a filter used for a vacuum-pumping system and the vacuum-pumping system. The filter comprises a filter body which is hollow and is opened at two sides, and a top cover which is detachably and hermetically connected with one side of the filter body, wherein a channel for allowing oil liquid not be filtered to pass through is formed inside the top cover, an outlet of the channel is covered with a cleanable filter screen assembly, and the cleanable filter screen assembly is arranged inside the filter body and can be drawn out from the interior of the filter body along with the top cover. The vacuum-pumping system is provided with the filter used. Through the structure including the top cover which is detachably and hermetically connected with one side of the filter body and the cleanable filter screen assembly capable of being drawn out from the interior of the filter body along with the top cover, the filter is relatively convenient to detach and clean, so that the service life of the filter is prolonged, and the use cost of the filter is lowered.