To explore a new process for mixing composite solid propellant slurry and address the safety assessment issues related to the process of mixing HTPB-based propellant two-component slurry in a static mixer， a low-burning-rate HTPB propellant with 85% solid content was selected as the research object. The limiting impact energy and limiting friction load of the binder slurry， curing agent slurry， and their mixed slurry were determined using BAM impact and friction sensitivity tests. Through force analysis and calculations during the pipeline transportation of the slurry and the mixing process in the static mixer， the driving pressure and friction force exerted on the slurry were compared with its limiting impact energy and limiting friction load， thereby obtaining safety assessment results. The results show that at 25 ℃， the limiting impact pressure sustainable by the curing agent slurry， binder slurry， and mixed slurry are 363 MPa， 363 MPa， and 325 MPa， respectively； the limiting friction loads sustainable are 128 N， 168 N， and 144 N， respectively. When the slurry inlet pressure is in the range of 0.4-0.5 MPa， and the temperature ranges from 25-45 ℃， the maximum driving pressures experienced by the binder slurry and curing agent slurry during pipeline transportation are 0.024 MPa and 0.046 MPa， respectively， and the maximum friction forces experienced are 6.11 N and 17.10 N. The maximum driving pressure experienced by the mixed slurry in the static mixer is 0.44 MPa， and the maximum friction force is 77.88 N. The binder and curing agent slurries are safe and reliable during pipeline transportation with a large safety margin； the mixed slurry exhibits good safety during the static mixer mixing process with a certain safety margin.