The present invention relates to a total luminous flux measurement system and a method thereof for measuring a total luminous flux of a light emitting component. The total luminous flux measurement system includes a light receiving module, a first light detector and a processing module. The light receiving module is disposed on a central normal of the light emitting component and divides a projection light field to a forward light field and a side light field. The light receiving module receives a beam in the forward light field to obtain a forward luminous flux. The first light detector is disposed on a side of the light receiving module to receive a beam in the side light field to obtain a first side luminous flux. The processing module electrically connects the light receiving module and the first light detector to calculate the total luminous flux at the light emitting component.