The invention discloses a lithium ion power battery as well as a manufacturing method, an electrolyte supplementing method and a gas exhausting method thereof. The manufacturing method comprises the following steps: connecting a plurality of single battery cores in series and parallel to assemble a module, and then performing a Pack process to manufacture the power battery; differences from a conventional power battery are that an electrolyte supplementing hole is formed in a top cover of each single battery core, a secondary electrolyte infusion tube for injecting electrolyte and exhausting gas is arranged in the electrolyte supplementing hole; one end of the secondary electrolyte infusion tube remote from the electrolyte supplementing hole is connected with a primary electrolyte infusiontube; a tube inserting opening is formed in a battery housing; and the primary electrolyte infusion tube penetrates the battery housing from the tube inserting opening so as to form a communicated electrolyte infusion network inside a battery pack. The invention provides the lithium ion power battery capable of supplementing electrolyte and exhausting gas as well as the manufacturing method and ause method of the lithium ion power battery, which ensure that the electrolyte can be infused into the single battery core through the electrolyte supplementing hole for immersing the bare battery core and discharging internal generated gas so as to supplement electrolyte into and exhaust gas from the power battery, and are simple to operate so as to prolong service life of the battery and make the battery have higher safety.