Simulating　the　human　brain　for　neuromorphic　computing　has　attractive　prospects　in　the　field　of　artificial　intelligence.　Optoelectronic　synapses　have　been　considered　to　be　important　cornerstones　of　neuromorphic　computing　due　to　their　ability　to　process　optoelectronic　input　signals　intelligently.　In　this　work,　optoelectronic　synapses　based　on　all-inorganic　perovskite　nanoplates　are　fabricated,　and　the　electronic　and　photonic　synaptic　plasticity　is　investigated.　Versatile　synaptic　functions　of　the　nervous　system,　including　paired-pulse　facilitation,　short-term　plasticity,　long-term　plasticity,　transition　from　short-　to　long-term　memory,　and　learning-experience　behavior,　are　successfully　emulated.　Furthermore,　the　synapses　exhibit　a　unique　memory　backtracking　function　that　can　extract　historical　optoelectronic　information.　This　work　could　be　conducive　to　the　development　of　artificial　intelligence　and　inspire　more　research　on　optoelectronic　synapses.