Soluble　β-glucan　from　mushroom　source　had　good　biological　activity,　in　order　to　develop　and　utilize　β-glucan　(CMBG)　in　Cordyceps　chrysanthemi,　this　study　used　Cordyceps　chrysanthemi　substrate　as　raw　material,　and　was　purified　by　proteolytic　enzyme　digestion,　adsorption　of　macroporous　resin,　and　chromatography　of　DEAE　ion-exchange　columns,　and　the　decolorization　rate　and　β-glucan　retention　rate　were　weighted　and　scored　to　feel　out　the　establishment　of　the　optimal　purification　process　conditions.　The　obtained　β-glucan　was　structurally　analyzed　and　its　in　vitro　hypoglycemic　activity　was　investigated.　The　results　showed　that　the　macroporous　resin　HPD-750　had　the　best　adsorption　effect,　and　the　optimal　conditions　for　adsorption　were　as　follows:　up-sample　flow　rate　of　5　mL/min,　up-sample　concentration　of　4　mg/mL,　up-sample　volume　of　400　mL,　and　mass　of　the　resin　of　40　g.　Two　β-glucan　fractions,　CMBG-1　and　CMBG-2,　with　relative　molecular　weights　of　13.57×104　Da　and　14.36×104　Da,　respectively,　were　isolated　using　a　DEAE-FF　cellulose　exchange　column.　Both　consisted　of　three　monosaccharides,　Gal,　Glc,　and　Man,　with　molar　ratios　of　1.28:5.27:1.01　and　0.71:4.43:0.80,　respectively.　The　Congo　red　analysis　showed　that　CMBG-1　had　a　triple-helix　structure,　while　CMBG-2　had　no　triple-helix　structure,　and　the　inhibition　rates　of　both　of　them　on　α-amylase　and　α-glucosidase　were　positively　correlated　with　the　concentrations　of　the　samples,　and　the　IC50　of　their　inhibition　on　α-amylase　were　2.68　and　4.32　mg/mL,　and　those　on　α-glucosidase　were　2.37　and　3.01　mg/mL,　respectively.　The　hypoglycemic　activity　of　CMBG-1,　which　possessed　a　triple-helix　structure,　was　significantly　higher　than　that　of　CMBG-2,　which　did　not　possess　a　triple-helix　structure,　and　it　had　good　prospects　for　the　development　of　functional　foods.　©　The　Author(s)　2025.