A light source assembly includes a first and a second light source modules. The first light source module includes a first light source, a first heat-dissipating base, and a first connecting part. The first heat-dissipating base has a first side and a second side. The first light source is mounted on the first side of the first heat-dissipating base, and the first connecting part extends outwardly from the second side of the first heat-dissipating base. The second light source module includes a second light source, a second heat-dissipating base, and a second connecting part. The second heat-dissipating base has a first side and a second side. The second light source is mounted on the first side of the second heat-dissipating base, and the second connecting part extends outwardly from the second side. The first connecting part is detachably and slidably engaged with the second connecting part.