This paper proposes an improved miniaturized quasi-Yagi antenna that works in the 5G millimeter wave band. Compared with the traditional quasi-Yagi antenna, reasonable use of the layout can reduce the longitudinal space of the antenna, greatly reducing the size of the antenna to a size of 15 mm ×26mm×1mm.,This antenna achieves a measured 43.8%(23.7-37GHz) frequency bandwidth for voltage standing-wave ratio 2 has a wider bandwidth. The maximum measured gain of the antenna is 7.41dBi at 29GHz and yhe minimum is 4.44dBi at 32GHz .Meet the efficiency requirements of 5G millimeter wave mobile communication systems