Traditional　controlled-source　audio-frequency　magnetotellurics　(CSAMT)　radiates　symmetric　beams　using　a　grounded　symmetric　dipole　(GSD).　Only　a　tiny　fraction　of　radiant　energy　is　taken　advantage　of　during　the　far-field　(Ff)　observation　due　to　the　low　directivity　of　the　GSD.　In　order　to　enhance　the　signal-to-noise　ratio　(SNR)　during　the　Ff　observation,　it　is　necessary　to　reduce　the　transceiving　distance　(TD)　or　increase　the　transmitting　power　(TP),　but　both　methods　will　cause　many　problems.　Further,　when　using　the　tensor　method　for　observation,　GSDs　in　two　vertical　directions　will　be　employed　to　radiate　energy,　and　then　a　series　of　problems　will　occur　such　as　an　asymmetry　of　the　SNR　in　two　vertical　directions　if　the　geological　conditions　under　the　two　GSDs　vary　widely.　An　arithmetic　phase　difference　(APd)　weighting　asymmetric　beamforming　method　(ABFM)　in　CSAMT　is　proposed　in　this　paper,　which　uses　a　GSD　array　instead　of　a　single　GSD,　and　a　signal　with　APd　is　transmitted　to　control　the　wavefront　for　beam　steering.　A　significant　enhancement　(about　3　dB)　of　the　SNR　will　occur　by　collecting　the　radiant　energy　in　the　region　of　concern　(RoC)　using　ABFM.　The　analysis　and　simulation　results　demonstrate　that　under　the　premise　of　the　same　TD　and　TP,　the　ABFM　has　obvious　advantages　in　improving　energy　utilization　in　CSAMT.　In　other　words,　the　APd-weighted　ABFM　can　deal　with　a　complex　noise　environment　in　the　field　better　than　the　traditional　method.