Signal amplifier

The utility model discloses a signal amplifier. The signal amplifier comprises hinges, a signal inlet part, a signal line, a signal outlet part, fixing columns, an electronic component plate and a box body. The box body comprises an upper cover and a lower shell, the upper cover is connected with the lower shell through hinges, the signal inlet part is arranged on one side of the lower shell and connected with the signal line, the signal outlet part is arranged on the other side of the lower shell, the electronic component plate is connectively fixed in the lower shell through the fixing columns, and signals are transmitted to the box body via the signal line and the signal inlet part and amplified through the electronic component plate and are transmitted out via the signal outlet part. The signal amplifier is capable of improving stability of interflow of transmitting and receiving data signal links and high in applicability and wide in range, can be used in basements, garages, hidden machine rooms and the like and can be flexibly configured according to specific application places.