NiFeMo　is　prevalently　employed　in　the　field　of　aerospace　and　electronic　devices　owing　to　its　excellent　soft　magnetic　properties.　Besides,　the　incorporation　of　elements　through　in-situ　alloying　presents　a　novel　strategy　for　performance　modulation　in　Selective　Laser　Melting　(SLM),　presenting　a　novel　pathway　toward　the　advancement　of　soft　magnetic　materials.　In　this　study,　(NiFeMo)100-xCrx　alloys　(x=0　wt%,　0.5　wt%,　1.0　wt%,　1.5　wt%,　2.0　wt%,　2.5　wt%)　were　prepared　utilizing　Cr　in-situ　alloying　SLM.　The　magnetic　properties　as　well　as　microstructural　characterization　were　conducted　by　employing　X-ray　diffraction　(XRD),　scanning　electron　microscopy　(SEM),　electron　backscatter　diffraction　(EBSD),　high-resolution　transmission　electron　microscopy　(HRTEM)　(Tecnai-G2F30),　and　direct　current　B-H　hysteresis　curve　testing　equipment　(MATS-2010S).　The　results　indicate　that　the　microstructure　of　the　SLM-formed　NiFeMo　alloy　through　in-situ　chromium　alloying　is　predominantly　characterized　by　columnar　grains　growing　along　the　build　direction.　With　an　increase　in　the　in-situ　alloying　ratio　of　chromium,　the　lattice　parameters　of　the　FCC　phase　structure　of　the　NiFeMo　alloy　decrease　from　3.582　&　Aring;　to　3.503　&　Aring;,　the　average　grain　size　monotonically　decreases,　and　the　maximum　texture　strength　monotonically　weakens.　Furthermore,　during　the　in-situ　alloying　SLM　process,　chromium　is　dissolved　into　the　FCC　gamma-(Ni,　Fe)　of　the　NiFeMo　alloy,　forming　dispersed,　chromium-rich　precipitates　of　larger　sizes.　This　leads　to　a　reduction　in　the　intrinsic　magnetic　properties　of　the　NiFeMo　alloy,　affecting　the　exchange　coupling　interaction　between　magnetic　atoms　and　the　motion　of　magnetic　domains.　Compared　to　the　NiFeMo　alloy,　the　saturation　magnetization　of　the　(NiFeMo)97.5Cr2.5　alloy　is　reduced　to　0.4685　T,　and　the　coercive　force　is　increased　to　37.7　A/m.　However,　when　the　chromium　content　is　1　wt%,　the　initial　magnetic　permeability　of　the　(NiFeMo)99Cr1　alloy　is　2.337　mH/m,　which　is　an　enhancement　of　1.9422　mH/m　compared　to　the　NiFeMo　alloy.