Owing　to　the　high　sensitivity　and　high　spatial　resolution,　fluorescence　(FL)　imaging　has　been　widely　applied　for　visualizing　biological　processes.　To　gain　insight　into　molecular　events　on　deeper　tissues,　photoacoustic　(PA)　imaging　with　better　deep-tissue　imaging　capability　can　be　incorporated　to　provide　complementary　visualization　and　quantitative　information　on　the　pathological　status.　However,　the　development　of　activatable　imaging　probes　to　achieve　both　FL　and　PAsignal　amplification　remains　challenging　because　the　enhancement　oflight　absorption　in　PA　imaging　often　caused　the　quenching　of　FL　signal.Herein,　wefirst　developed　a　caspase-3　enzyme　activatable　nanoprobe　ofa　nanogapped　gold　nanoparticle　coated　with　AIE　molecule　INT20　andDEVD　peptides　(AuNNP@DEVD-INT20)　for　tumor　FL　and　PAimaging　and　subsequent　imaging-guided　radiotherapy.　The　nanoprobecould　interact　with　GSH　and　caspase-3　enzyme　to　liberate　INT20　molecules,　leading　to　AIE.　Simultaneously,　thein　situself-assembly　of　AuNPs　was　achieved　through　the　cross-linking　reaction　between　the　sulfhydryl　and　the　maleimide,　resulting　in　ratiometric　PAimaging　in　tumor.　Remarkably,　the　nanoprobe　can　generate　richful　ROS　for　cancer　radiotherapy　under　X-ray　irradiation.　The　platform　not　only　achieves　the　aggregation-induced　FL　and　PA　signal　enhancement　but　also　provides　a　general　strategy　for　imaging　of　various　biomarkers,　eventually　benefiting　precise　cancer　therapy.