To investigate the reaction-growth behavior of propellant and polymer-bonded explosive （PBX） under mass-inertial confinement following non-shock ignition， a thick-walled cylinder/mass-block experimental configuration was developed. Laser ignition was used to initiate the reaction. Multiple photonic Doppler velocimetry （PDV） probes were arranged to synchronously measure the radial expansion velocity of the cylinder and the axial velocity of the top surface of the mass block. High-speed imaging was also employed. Post-test residue recovery and examination were further conducted to comparatively analyze the reaction-evolution process. The results show that mass-inertial confinement intensifies the early-stage pressurization during reaction growth. Under identical confinement conditions， however， the type of energetic material governs the reaction-growth characteristics and reaction violence. In the propellant tests， the early-stage pressurization is dominated by mass-inertial confinement. The system response is characterized primarily by axial motion of the mass block， and no yielding deformation occurs in the thick-walled cylinder. The peak reaction pressure remains below 50 MPa， the reacted fraction is less than 1%， and nearly all of the propellant is recovered， indicating a burning event. In the PBX tests， the early-stage pressurization is jointly governed by mass-inertial confinement and structural confinement. The cylinder undergoes yielding and radial expansion， while the mass block exhibits axial motion accompanied by local upsetting deformation. The peak reaction pressure reaches 2 GPa， the reacted fraction exceeds 50%， and no explosive residue is recovered， indicating a violent explosive reaction.