Abstract: Hard X-ray Modulation Telescope (HXMT) was Chinese first space astronomy satellite, which was launched into 550km orbit with inclination of 43° in June 2017. The Space Environment Monitor on HXMT was designed to provide measurements of energetic protons and electrons. The detector is an all solid-state system that can make 16-directional flux measurements of electrons with energy ≥ 200keV and protons with energy ≥ 1.5MeV, and can also measure the differential energy spectra of electrons from 0.4 to >1.5MeV and protons from 3 to 300MeV with 7 channels separately from single direction. The detector can characterize particles distribution for detail especially in SAA which is important for low Earth orbit missions. The primary observations provide relative comprehensive particles global distributions, and demonstrate that particles radiation are mainly observed in SAA within longitude 80°W-20°E and latitude 0°-40°S, and electrons in SAA show stronger anisotropy than protons, the SEP occurred in September 2017 had no effect on the orbit, while the magnetic storm in early time before the SEP induced electrons enhancement in narrow region within longitude 120°W-60°E and latitude 40°-43°N over North America and longitude 60°-120°E and latitude 40°-43°S over South-West Australia. The electrons showed intensive anisotropy.