Magnesium　phosphate　cement-based　reactive　powder　concrete　(MPC-RPC)　is　a　cement-based　material　with　early　strength,　high　strength　and　excellent　durability.　The　slump　flow　and　setting　time　of　steel　fibers　reinforced　MPC-RPC　are　investigated.　Meanwhile,　the　flexural　strength,　the　compressive　strength,　the　ultrasonic　velocity　and　the　electrical　resistivity　of　specimens　cured　for　3　h,　1　day,　3　days　and　28　days　are　determined.　Moreover,　the　corresponding　corrosion　resistance　reinforced　MPC-RPC　exposing　to　NaCl　freeze-thaw　(F-T)　cycles　and　dry-wet　(D-W)　alternations　is　researched.　In　this　study,　the　steel　fibers　used　are　0%,　0.5%,　1.0%,　1.5%,　2.0%,　2.5%　and　3.0%　by　the　volume　of　MPC-RPC.　The　corrosion　of　the　inner　reinforcement　is　reflected　using　the　mass　loss,　electrical　resistivity,　ultrasonic　velocity,　and　the　AC　impedance　spectrum.　Researching　findings　show　that　the　steel　fibers　lead　to　decreasing　the　slump　flow　and　setting　time.　The　flexural　strength,　the　compressive　strength　and　ultrasonic　velocity　of　MPC-RPC　cured　for　3　h　are　higher　than　45%　of　the　MPC-RPC　cured　for　28　days.　Moreover,　when　the　MPC-RPC　is　cured　for　7　days,　the　flexural　strength,　the　compressive　strength　and　ultrasonic　velocity　of　MPC-RPC　are　higher　than　85%　of　the　specimens　cured　for　28　days.　The　electrical　resistance　decreases　in　a　quadratic　function　as　the　volume　ratio　of　steel　fibers　increases.　The　corrosion　resistance　of　the　internal　reinforcement　can　be　improved　by　adding　steel　fibers　at　appropriate　dosages.　The　reinforcement　inner　MPC-RPC　corrodes　more　seriously　under　the　NaCl　D-W　alternations　than　NaCl　F-T　cycles.　©　2022　by　the　authors.