The industrial action is due to take place on October 1 and October 5, as part of a long running dispute over pay.
Tory MPs and thousands of party members are due to gather in Birmingham from October 2-5.
The strikes will therefore disrupt those travelling to the annual gathering as then going home afterwards.
Truss is due to deliver her keynote address to the conference at Wednesday lunchtime.
A planned strike by drivers on September 15 was called off as a mark of respect following the Queen’s death.
The drivers’ union Aslef will not be making a public comment until after the late monarch’s funeral on Monday.
Industrial disputes in the rail industry and other sectors, including post and telecoms, have led to a summer of strikes, which are set to resume in the coming weeks.
HuffPost UK revealed earlier this week that the Tory conference is going ahead despite suggestions it could be cancelled due to the death of the Queen.
Labour’s conference at the end of September is also going ahead. But the Lib Dems cancelled their meeting as it coincided with the Queen’s funeral on Monday.
Conservative sources said the party is planning “a number of things” to mark the Queen’s passing.
It is understood they will include a minute’s silence, as well as the playing of the national anthem.