A speaker and earplug earphones are provided. The speaker includes a cylindrical speaker housing. A partition board arranged along a radial direction is disposed in an enclosed cavity. A first speaker and a second speaker are respectively disposed on both sides of the partition board, and each includes a magnetic circuit system and a vibrating system. A magnetic gap is disposed between the magnetic circuit system and the speaker housing, and an air pressure balance holes are formed in the partition board located at the magnetic gap. The vibrating system includes a voice coil and a vibrating diaphragm covering the end part of the speaker housing. Each earplug earphone includes an earphone front housing and an earphone back housing. The speaker is mounted in the enclosed space. Multiple front housing sound output holes is formed in the earphone front housing. An acoustic waterproof membrane is disposed between the multiple front housing sound output holes and the speaker.