A method for implementing video recording retrieval performed by a device for implementing the video recording retrieval within a frame of a network video surveillance, NVS, service, wherein the network comprises the device, an alarm device, a camera, and a server, the method comprising: for each of multiple alarm events performing the following steps a.) - d.): a.) receiving (no) the alarm event from the alarm device, wherein the alarm event comprises a device identifier of the alarm device and an alarm occurrence time; b.) determining a camera identifier according to the device identifier, wherein the camera identifier is an identifier of the camera for capturing a video recording corresponding to the alarm event; c.) determining video recording time information of the video recording according to the alarm occurrence time, and generating (120, 130) a video recording bookmark and a video recording index of the video recording, wherein the video recording bookmark comprises the camera identifier and the alarm occurrence time, and the video recording index comprises the video recording time information and acquisition information of the video recording, wherein the acquisition information of the video recording is information configured for obtaining the video recording associated with the alarm event and is indicated by location information of the server that stores the video recording and a storage path of the video recording; d.) storing the video recording bookmark and the video recording index in an associative manner by: storing the video recording bookmark and assigning a bookmark identifier to the video recording bookmark, storing the video recording index and assigning an index identifier to the video recording index, and recording an association relationship between the bookmark identifier and the index identifier, e.) receiving a video recording retrieval request from a terminal, wherein the video recording retrieval request comprises a retrieval condition, and the retrieval condition comprises: ∘ a camera identifier, or ∘ alarm time information indicating a time segment used for retrieving a video recording corresponding to an alarm event that occurs at an alarm occurrence time within the time segment; f.) searching for a video recording bookmark that meets the retrieval condition among the stored video recording bookmarks, determining a bookmark identifier among the stored bookmark identifiers corresponding to the video recording bookmark meeting the retrieval condition, determining, based on the stored association relationship between the bookmark identifier and the index identifier an index identifier corresponding to the determined bookmark identifier, and determining a video recording index, among the stored video recording indices, corresponding to the determined index identifier; and g.) returning the determined video recording index to the terminal. a.) receiving (no) the alarm event from the alarm device, wherein the alarm event comprises a device identifier of the alarm device and an alarm occurrence time; b.) determining a camera identifier according to the device identifier, wherein the camera identifier is an identifier of the camera for capturing a video recording corresponding to the alarm event; c.) determining video recording time information of the video recording according to the alarm occurrence time, and generating (120, 130) a video recording bookmark and a video recording index of the video recording, wherein the video recording bookmark comprises the camera identifier and the alarm occurrence time, and the video recording index comprises the video recording time information and acquisition information of the video recording, wherein the acquisition information of the video recording is information configured for obtaining the video recording associated with the alarm event and is indicated by location information of the server that stores the video recording and a storage path of the video recording; d.) storing the video recording bookmark and the video recording index in an associative manner by: storing the video recording bookmark and assigning a bookmark identifier to the video recording bookmark, storing the video recording index and assigning an index identifier to the video recording index, and recording an association relationship between the bookmark identifier and the index identifier, e.) receiving a video recording retrieval request from a terminal, wherein the video recording retrieval request comprises a retrieval condition, and the retrieval condition comprises: ∘ a camera identifier, or ∘ alarm time information indicating a time segment used for retrieving a video recording corresponding to an alarm event that occurs at an alarm occurrence time within the time segment; ∘ a camera identifier, or ∘ alarm time information indicating a time segment used for retrieving a video recording corresponding to an alarm event that occurs at an alarm occurrence time within the time segment; f.) searching for a video recording bookmark that meets the retrieval condition among the stored video recording bookmarks, determining a bookmark identifier among the stored bookmark identifiers corresponding to the video recording bookmark meeting the retrieval condition, determining, based on the stored association relationship between the bookmark identifier and the index identifier an index identifier corresponding to the determined bookmark identifier, and determining a video recording index, among the stored video recording indices, corresponding to the determined index identifier; and g.) returning the determined video recording index to the terminal.