Which will be prioritized when I input synchronized signals to both of MIDI IN and TRIGGER IN?

RIGGER IN is prioritized based on parameter setting at [Seq Jack Mode] of the [GLOBAL SETTING] menu either you set [Master] or [Slave] for this unit at the MIDI CLOCK setting.
For details, see "Changing the unit settings ([GLOBAL SETTING])" and "Using the [TRIGGER IN] of this unit to control the play functions of this unit" in the Operating Instructions of this unit.
You can download the Operating Instructions from the Pioneer DJ support page.