Magnetic random-access memory (MRAM) provides a promising candidate for the next-generation memory technology with high-energy efficiency and fast operation speed. Spin splitting band structure in nonrelativistic collinear antiferromagnet with de-coupled crystal and spin symmetry provides a unique way for the flexible and efficient control of the polarization and flow directions of the spin current. Here, by integrating the potential altermagnetic (101)-RuO2 writing channel with the magnetic tunnel junction (MTJ) device, we demonstrate the all-electrical field-free altermagnetic spin splitting torque (SST)-driven switching of the perpendicular-MTJ in the 3-terminal altermagnetic SST-MRAM device, with the tilted spin polarization and the transversal flow of the spin current. The z-spin torque is further characterized by the altermagnetic SST-induced shift of the magnetic hysteresis loop, and the field-free altermagnetic SST-driven magnetic domain switching of the recording layer is directly observed by the magneto-optic Kerr effect (MOKE) microscope. Our research establishes groundwork for advancing the development of the altermagnetic SST-MRAM, paving the way for the future all-electrical, energy-efficient and high-endurance MRAM applications with separated writing/reading channels.