The invention discloses a million-level network session table management method, system, medium and device based on a Hash algorithm, and the method comprises the steps: carrying out the pre-distribution of all continuous memory spaces according to the preset session table capacity, and carrying out the initialization; Enabling the available session table units to form an available node link table; When the session table unit is deleted, the node memory is not released to the operating system, and the available node link table is reentered for the use of a new session; When a certain data packet is collected, judging whether a session corresponding to the data packet is created or not; Determining different sessions through the quintuple information, and associating the data packets with the sessions; The method comprises the following steps of: combining and converting quintuple information to finally form a 32-bit numerical characteristic, and carrying out hash value calculation based on the characteristic to serve as a session hash linked list main key, thereby quickly positioning the position of the session list. The session corresponding to a certain data packet can be quicklypositioned in real time, and the session information can be updated.