A system for releasing locking of a fusion splicer includes a fusion splicer, an information terminal, and a server. The fusion splicer locks a fusion-splicing function in accordance with a predetermined lock condition and releases the locked function in accordance with a release command input. The server includes a storage unit that stores authentication information provided by a user of the fusion splicer, a collation unit that collates authentication information provided from the information terminal with the authentication information stored in the storage unit, and a password issuance unit that issues a one-time password including at least a date in an algorithm when a collation result is favorable. The information terminal authenticates the one-time password in consideration of a day difference or a time difference between the information terminal and the server and applies the release command to the fusion splicer when an authentication result is favorable.