  A comprehensive study is given to short gamma-ray bursts (sGRBs) in the third
Swift/BAT GRB Catalog from December 2004 to July 2019. We examine in details
the temporal properties of the three components in the prompt gamma-ray
emission phase, including precursors, main peaks and extended emissions (EE).
We investigate the similarity of the main peaks between one-component and
two-component sGRBs. It is found that there is no substantial difference among
their main peaks. Importantly, comparisons are made between in the
single-peaked sGRBs and the double-peaked sGRBs. It is found that our results
of main peaks in Swift/BAT sGRBs are essentially consistent with those in
CGRO/BATSE ones recently found in our paper I. Interestingly, we suspect,
besides the newly-found MODE I/II evolution forms of pulses in BATSE sGRBs in
paper I, that there would have more evolution modes of pulses across
differently adjacent energy channels in view of the Swift/BAT observations. We
further inspect the correlation of the main peaks with either the precursors or
the EEs. We find that the main peaks tend to last longer than the precursors
but shorter than the EEs. In particular, we verify the power-law correlations
related with peak fluxes of the three components, strongly suggesting that they
are produced from the similar central engine activities. Especially, we compare
the temporal properties of GRB 170817A with other sGRBs with EE and find no
obvious differences between them.
