The recent discovery of high-temperature superconductivity in the bilayer nickelate La₃Ni₂O₇ under high pressure has drawn significant attention, further catalyzing intensive research on nickel-based superconductors. Systematic comparative studies of unconventional superconductors are vital for advancing the mechanistic understanding of high-T_c superconductivity. In contrast to cuprates, bulk nickelates exhibit significant differences in crystal structure, electronic properties, and physical behaviors, and their experimental investigation faces specific challenges including the influences of hydrostatic conditions on the measurements of zero resistance and diamagnetic response, oxygen vacancy defects in single crystals, and pressure-induced structural phase transitions. This review comprehensively examines high-temperature superconductivity and the related research challenges in trilayer nickelate bulk materials, and provides experimental insights for future studies on nickel-based superconducting systems.