As　a　new　technology　for　hydrogen　transporting,　hydrogen　and　compressed　nature　gas　(HCNG)　has　significance　on　the　realization　of　large-scale　hydrogen　transportationby　pipeline　network.　However,　the　presence　of　hydrogen　will　lead　to　the　mechanical　properties　degradation　of　pipeline　metal,　which　seriously　threatens　the　safe　use　of　pipeline　network.　X52　pipeline　steel　was　chosen　as　the　research　object.　The　influence　of　hydrogen　charging　current　density　on　the　tensile　property　of　X52　was　studied　by　simultaneous　cathodic　charging　and　slow　straining　rate　test.　The　influence　of　electrolytic　hydrogen　environment　on　crack　growth　rate　of　X52　was　studied　through　fatigue　crack　growth　test.　In　addition,　the　fracture　morphology　of　tensile　and　fatigue　specimens　was　observed　by　means　of　SEM　to　analyze　the　mechanism　of　X52　hydrogen　embrittlement　fracture.　Test　results　show　that　electrochemical　hydrogen　charging　has　effect　on　mechanical　properties　of　X52.　As　charging　current　density　elevates,　the　strength　of　materials　enhances　slightly　but　its　plasticity　decreases　significantly.　Changes　in　the　microstructure　of　the　tensile　specimen　section　indicated　that　the　fracture　mode　of　material　transforms　from　dimple　ductile　fracture　to　quasi-dissociative　brittle　fracture　with　elevated　hydrogen　charging　current　density.　Electrolytic　hydrogen　environment　will　accelerate　the　crack　growth　rate　of　X52.　Micro　fractures　indicate　that　hydrogen　embrittlement　mechanism　dominates　the　crack　propagation　process.　©　2020,　Materials　Review　Magazine.　All　right　reserved.