Thank you very much.
by the way,the WIKI provides ocr-transformers-context.xml is old, it can not work with Alfresco that i checkout from svn
the problem this
<property name="explicitTransformations">
<list>
<bean class="org.alfresco.repo.content.transform.ContentTransformerRegistry$TransformationKey" >
<constructor-arg><value>image/tiff</value></constructor-arg>
<constructor-arg><value>application/pdf</value></constructor-arg>
</bean>
</list>
</property>
should be
<property name="explicitTransformations">
<list>
<bean class="org.alfresco.repo.content.transform.ExplictTransformationDetails">
<constructor-arg><value>application/pdf</value></constructor-arg>
<constructor-arg><value>image/tiff</value></constructor-arg>
</bean>
</list>
</property>
