Despite　the　growth　in　the　number　of　older　drivers　and　accidents,　there　is　still　a　lack　of　clarity　about　the　risk　of　elderly-related　accidents　in　China.　Cognitive　function　is　an　important　factor　affecting　driving　behavior.　This　study　links　cognitive　function　and　driving　behavior,　aiming　to　explore　the　micro　cognitive　driving　behavior　characteristics　of　older　drivers.　An　emergency　event　of　sudden　lane-changing　of　the　leading　vehicle　is　set　in　a　driving　simulator.　18　younger　and　20　older　drivers　participate　in　the　testing　and　their　driving　behavior　data　are　used　to　build　trajectory　graphs.　It　can　be　observed　that　older　drivers　have　more　risk　of　behavioral　changes.　Further,　the　subjects＇　collision　avoidance　responses　are　divided　into　perception,　judgment,　and　operation　stages　to　reveal　the　mechanism　of　cognitive　action　on　driving　response.　In　contrast　to　the　younger,　older　drivers　have　longer　braking　reaction　time,　smaller　braking　speed,　larger　minimum　braking　acceleration,　and　smaller　maximum　steering　wheel　speed.　Based　on　these　characteristics　of　older　drivers,　some　age-appropriate　vehicle　designs　and　interventions　have　been　proposed　to　improve　their　driving　safety.　This　study　contributes　to　better　understanding　the　essence　of　risky　driving　behavior　of　older　adults,　and　provides　a　basis　for　the　formulation　of　management　measures.