Thermally activated delayed fluorescence (TADF) materials enable nearly 100% internal quantum efficiency in organic light-emitting diodes (OLEDs) by harvesting both singlet and triplet excitons via reverse intersystem crossing (RISC). However, their practical application is severely hindered by the efficiency roll-off caused by prolonged delayed fluorescence lifetime, which enhances non-radiative decay and exciton quenching. Traditional modulation methods including molecular design and host-guest engineering suffer from complex synthesis and limited lifetime tuning effects. High-pressure engineering, as a powerful tool to regulate molecular packing and electronic structures, provides a feasible strategy to solve this problem. Herein, we systematically studied the pressure-dependent photophysical properties of 3,4,5,6-tetrakis(carbazol-9-yl)-1,2-dicyanobenzene (4CzPN), a typical donor-acceptor TADF crystal, using in-situ high-pressure photoluminescence (PL), time-resolved PL, infrared (IR) spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Under compression, the PL intensity continuously decreases due to strengthened non-radiative transitions, while the emission peak shows a remarkable red-shift of approximately 130 nm up to 10.56 GPa, originating from pressure-induced molecular conformational planarization and enhanced intramolecular charge transfer. The luminescence color changes from bright yellow to red and recovers completely after pressure release, demonstrating reversible piezochromism. Time-resolved spectra reveal that the delayed fluorescence lifetime shortens from 2.62 µs at ambient pressure to full quenching above 2.5 GPa, accompanied by a synchronous decrease in prompt fluorescence lifetime. Excited-state dynamic calculations illustrate that high pressure elevates spin orbit coupling (SOC) and enlarges the singlet-triplet energy gap (ΔE_ST). The increased SOC dominates the accelerated RISC rate, whereas the reduced T₁ state density induced by molecular planarization significantly suppresses the intersystem crossing (ISC) rate. The synergy of enhanced RISC and weakened ISC directly accounts for the shortened delayed fluorescence lifetime. High-pressure IR spectra show that all characteristic absorption peaks blue-shift with increasing pressure, indicating compressed bond lengths and strengthened intermolecular interactions, which promote non-radiative relaxation and reduce PL intensity. The reversible IR spectral changes confirm the structural stability of 4CzPN crystals during pressure cycles. This work proves that high-pressure engineering can effectively modulate the fluorescence lifetime and luminescence behavior of TADF materials by tuning excited-state dynamics and molecular structures. The suppression of delayed fluorescence lifetime alleviates the efficiency roll-off of OLEDs, offering a novel approach for optimizing organic optoelectronic devices and developing pressure-responsive luminescent materials.