  Direct laser cooling and trapping of molecules to temperature below Doppler
limit and density exceeding $10^8$ are challenging due to the sub-Doppler
heating effects of molecular magneto-optical trap (MOT). In our previous paper
[1], we presented a general approach to engineering the sub- Doppler force by
tuning the AC stark shift with the addition of a blue detuned laser. Here, by
employing the Bayesian optimization method to optical Bloch equations, we have
identified multiple blue-detuned MOT schemes for the CaF molecule. From the
three-dimensional Monte-Carlo simulation, we obtained a MOT temperature and
density of 14 $\rm \mu K$ and $\rm 4.5 \times 10^8 cm^{-3}$, respectively. Our
findings present a potential avenue for directly loading molecular MOTs into
conservative traps, which can capitalize on the high density and low
temperature of the MOT
