A filter holding system for holding an optical filter to a mask casing of a welding mask. The filter holding system can include a holding frame body configured for supporting and accommodating the optical filter, and a connecting mechanism which is provided on the holding frame body and is configured for connecting or disconnecting the holding frame body to or from the mask casing. The connecting mechanism can have a disconnect position and a connect position. In the disconnect position, the connecting mechanism disconnects the holding frame body from the mask casing, and in the connect position, the connecting mechanism connects the holding frame body and the mask casing. A welding mask can comprise a mask casing, a headgear, a protective film, an optical filter and a filter holding system.