In this study, a series of TC4 alloy single tracks were prepared by electron beam melting, the process parameters such as scanning speed, beam current, and focus offset were adjusted to investigate the influence of process parameters on the surface morphology and geometrical characteristics (re-melt depth, track width, track height, contact angle and aspect ratio) of a single track. The results showed that the linear energy input increased with the decrease of scanning speed and the increase of beam current, the width and continuity of single tracks were improved. When other parameters were fixed, with the increase of scanning speed, the single track became discontinuous and even the balling effect could be observed. The scanning speed, beam current, and focus offset all have a great influence on the melt pool, with the decrease of scanning speed and the increase of beam current, the re-melt depth, track width, and track height increased. When the focus offset was 3mA, the re-melt depth and track width were maximum while the contact angle was the minimum. For the constant of beam current, with the increase of scanning speed, the contact angle increased first and then decreased while the aspect ratio decreased.