  Magnetars are neutron stars with extreme magnetic field and sometimes
manifest as soft gamma-ray repeaters (SGRs). SGR J1935+2154 is one of the most
prolific bursters and the first confirmed source of fast radio burst (i.e. FRB
200428). Encouraged by the discovery of the first X-ray counterpart of FRB,
Insight-Hard X-ray Modulation Telescope (Insight-HXMT) implemented a dedicated
33-day long ToO observation of SGR J1935+2154 since April 28, 2020. With the
HE, ME, and LE telescopes, Insight-HXMT provides a thorough monitoring of burst
activity evolution of SGR J1935+2154, in a very broad energy range (1-250 keV)
with high temporal resolution and high sensitivity, resulting in a unique
valuable data set for detailed studies of SGR J1935+2154. In this work, we
conduct a comprehensive analysis of this observation including detailed burst
search, identification and temporal analyses. After carefully removing false
triggers, we find a total of 75 bursts from SGR J1935+2154, out of which 70 are
single-pulsed. The maximum burst rate is about 56 bursts/day. Both the burst
duration and the waiting time between two successive bursts follow log-normal
distributions, consistent with previous studies. We also find that bursts with
longer duration (some are multi-pulsed) tend to occur during the period with
relatively high burst rate. There is no correlation between the waiting time
and the fluence or duration of either the former or latter burst. It also seems
that there is no correlation between burst duration and hardness ratio, in
contrast to some previous reports. In addition, we do not find any X-ray burst
associated with any reported radio bursts except for FRB 200428.
