The semi-airborne transient electromagnetic realizes the detection of underground structures by arranging loop source on the ground and using UAV equipped with receiving coils to get signals. However, the response will be affected by the flight height and reception offset in the actual application. Aiming at this problem, the research on the spatial distribution of semi-airborne transient electromagnetic response is carried out. Firstly, the influence of different factors on the electromagnetic response is analyzed by using the method of control variables with the forward calculation of the uniform earth model and the layered earth model; Secondly, through the forward calculation of the model with abnormal body, the influence of parameters such as the buried depth and resistivity of the abnormal body on the ability of the semi-airborne transient electromagnetic exploration underground target body is analyzed. The results show that the effects of flight height and offset on the semi-airborne transient electromagnetic response are mainly concentrated in the early stage. With the increase of the flight height or the offset, the amplitude of the early vertical induced electromotive force gradually decreases, and the polarity reversal phenomenon occurs in the external response of the loop source. The response curve shows different decay rates in different resistivity formations, which indicates that it has a good identification effect on the formation resistivity change. The response curve can reflect the buried depth and resistivity of underground target body, which proves the ability of semi-airborne transient electromagnetic to distinguish different objects.