Combined　PM2.5　and　O-3　pollution　in　China　has　caused　negative　health　impacts　on　residents　and　reduced　crop　yields.　The　quantitative　assessment　and　prediction　of　these　impacts　could　provide　a　scientific　basis　for　policy　development.　This　study　assessed　the　nationwide　premature　mortality,　health　effects,　and　crop　damage　attributable　to　PM2.5　and　O-3　pollution　in　2019,　and　projected　the　associated　health　and　agricultural　losses　under　a　business-as-usual　(BAU)　scenario　for　2025.　The　economic　benefits　of　improving　air　quality　under　different　policy　scenarios,　including　the　14th　Five-Year　Plan　(FFP),　Secondary　Standard　Limit　(SSL),　and　Primary　Standard　Limit　(PSL),　were　also　explored.　The　results　showed　PM2.5　pollution　in　2019　resulted　in　246,000　all-cause　premature　deaths　and　the　economic　health　loss　was　RMB　196.509　billion.　Similarly,　O-3　pollution　caused　186,300　premature　deaths　and　the　economic　health　loss　was　RMB　155.807　billion.　O-3　pollution　has　led　to　a　loss　of　28.5241　million　tonnes　of　crop　production　and　an　economic　loss　of　RMB　62.268　billion.　Compared　with　2019,　the　avoidable　premature　deaths　from　PM2.5　under　different　scenarios　in　2025　were　50,600,　43,000,　and　200,300　cases,　respectively,　exceeding　the　number　of　avoided　premature　deaths　from　O-3　pollution.　Compared　with　the　BAU,　reducing　PM2.5　under　different　scenarios　could　generate　economic　benefits　of　RMB　70.178　billion,　RMB　60.916　billion,　and　RMB　229.268　billion.　Furthermore,　the　FFP　scenario　outperformed　the　SSL　in　mitigating　winter　wheat　production　losses　caused　by　O-3　pollution.　These　results　provide　important　scientific　support　for　the　development　and　evaluation　of　future　comprehensive　pollution　control　measures　for　PM2.5　and　O-3.